(dissenting). I am unable to agree with the opinion of the majority. The defendant assigns error in the trial court’s overruling of its claim that “[t]he plaintiff never gave a statement under oath to the defendant indicating that she was hit by an uninsured automobile.” In the majority opinion the decision on this assignment of error is stated to be dispositive of this appeal. The fact that the statement to the defendant, notifying it of the accident, was not under oath is not in dispute. The trial court found that the defendant, by its conduct, waived the requirement of this notice under oath by failing to raise this claim by pleading it in a special defense and by failing to raise the issue at all until midway through the second trial in the Superior Court. The majority opinion recites that the failure to file a special defense may be treated as waived when it appears that no objection was raised to the offer of evidence on the issue at the trial. The majority opinion concludes with the statement that “[ujnder these circumstances, even assuming that the defendant failed properly to plead its defense of a lack of notice under oath, the defect in pleading is deemed to have been waived.” The majority of the court, “ [t] o be certain that justice is done,” consulted the transcript of the first trial. In so doing, it created a new issue concerning which there is noth*481ing in the printed record or in the transcript to indicate that any claim of waiver was made by the defendant at the trial or in this court. The plaintiff was thus deprived of any opportunity to contest the issue raised. The opinion also discusses the conclusion of the trial court that the defendant had waived its claim relating to a statement under oath by failing to raise the issue until midway through the second trial and finds no need to pass on the merits of whether such a course pursued by an insurer would constitute a waiver “since the defendant did not pursue such a course.”
The majority opinion predicates this conclusion on an examination of the record and briefs in the first appeal to this court. The reference is to volume A-468, Connecticut Supreme Court Records and Briefs, page 117, paragraph 53, wherein the defendant made the claim of law that “[t]he plaintiff failed to establish compliance with the conditions set out in . . . (Paragraph 5 of Finding) to qualify for coverage on the ‘uninsured vehicle’ and ‘hit and run’ clauses.” No mention is made there of the failure of the plaintiff to file with the defendant within thirty days a statement under oath. Ill the light of the defendant’s special defense such a claim could have no validity. In its special defense the defendant alleged that the plaintiff was not covered by liability insurance for two reasons: (1) because she exceeded the permission given her to operate the car covered by the policy and (2) in that she violated Part IV of the policy entitled “Uninsured Motorist Portion” in that she exceeded the permission granted her to drive the vehicle covered by the policy and that a hit-and-run accident did not occur as defined under this coverage. A-468 Rec. & Briefs 107. The entire special defense is printed in a *482footnote.1 Included in Part IV of the policy is the requirement of notice, under oath, to the insurer within thirty days. The defendant specified the portions of Part IV on which the special defense was predicated. It made no claim that the notice was improper because it was not under oath or for any other reason. Inclusio unius est exclusio alterius. To hold otherwise would be to permit trial by ambush. In the record of the first case there is no mention of the failure of the plaintiff to file with the defendant a statement under oath, nor does the defendant’s brief in that appeal make any such claim.
In Frager v. Pennsylvania General Ins. Co., 155 Conn. 270, 273, 231 A.2d 531, we said: “While the defendant, in its answer, specially denied each of the material allegations of the plaintiff’s application, apparently improperly and in violation of §§ 73, 116, 117 and 118 of the Practice Book, on this appeal it is conceded that the plaintiff is an insured party under the policy and that the only issue is whether the question of contact should be resolved, as the plaintiff claims, by the arbitrators or, as the defendant claims, by the trial court. The answer *483to this question depends upon the proper interpretation of the terms relating to arbitration as set forth in Part IV of the policy.” (Emphasis supplied.) This is a strong indication that this court, on the record, briefs and argument, was completely unaware of the present claim of the defendant as to lack of notice under oath. There was good reason for this inasmuch as the defendant had never raised the question nor had it made such a claim. In its brief in the first appeal the defendant specifically abandoned its attack on the findings of fact designed to raise an issue as to whether the plaintiff was an additional insured under the policy. A-468 Ree. & Briefs 117. It concluded as follows: “The order of arbitration should be reversed and a new hearing granted providing for a judicial determination of whether there was a collision with a hit and run automobile with the corollary right to a jury trial thereon.” A-468 Rec. & Briefs 126.
On remand of the case to the trial court the defendant, on July 24, 1968, filed an amended special defense which is recited in a footnote.2 If the defendant intended to make a claim of lack of notice it failed to indicate it in this amended pleading which was filed more than three years after receiving notice in writing of the plaintiff’s claim.
*484The trial court in the present case concluded, inter alia, that the defendant’s claim of law that the plaintiff never gave a statement under oath to the defendant indicating that she was hit by an uninsured vehicle was not before the court for two reasons: (1) the defendant waived such a claim by failing to raise it in a special defense, and (2) the defendant waived such a claim by failing to raise the issue at all until midway through the second trial.
The facts, as found by the trial court, together with the pleadings and the printed records of both appeals, are of importance in the determination of the question whether the conclusion of the trial court concerning waiver should be sustained. The following facts were found by the trial court: On April 22,1965, the plaintiff was involved in a motor vehicle accident while operating the ear of Page and Doris Porter, which she had borrowed from her cousin Mrs. Porter. As she was coming around a bend on Forest Road in the city of New Haven, traveling in a northerly direction, the car was struck near the back on the left side by another automobile traveling in a southerly direction which approached on the plaintiff’s side of the road. Thereafter, the car driven by the plaintiff hit a telephone pole which fell on top of the car. Neither the approaching car nor its driver has ever been identified. The plaintiff was seriously injured. At the scene of the accident she talked to a New Haven police sergeant and told him of the accident. She was removed to the hospital by ambulance. The police officer was advised that the plaintiff was in great pain and under the influence of a pain killer, demerol, and was told that in view of the plaintiff’s injuries he could not talk to her at that time. The *485plaintiff subsequently talked to the sergeant at the hospital. The day following the accident, on the third meeting of the plaintiff and the police sergeant, he was given a report of the accident by the plaintiff.
Prom these facts, together with the pertinent provisions of the policy, the trial court concluded that the unidentified automobile was an “uninsured automobile” within the terms of the policy; that there was contact between the unidentified car and the car driven by the plaintiff; that the plaintiff notified the police of the accident; that the plaintiff’s counsel and later, the plaintiff, advised the defendant that the plaintiff had been involved in an accident with an unidentifiable person. On May 19, 1965, the defendant was given notice by letter from the plaintiff’s attorney that the plaintiff had been injured by a hit-and-run driver who forced her off the road and struck the car of the defendant’s insureds, Page and Doris Porter, while it was being operated by the plaintiff. The letter made it perfectly clear that it was the plaintiff’s intention to avail herself of the uninsured motorist’s provision contained in the policy. It is clear from the letter that counsel, on May 6, 1965, had notified the insurance agent who sold the policy to the Porters, of the plaintiff’s injuries; and that on May 11, 1965, the Porters were notified in writing by the plaintiff’s counsel. On May 24,1965, receipt of the claim was acknowledged by the defendant’s claim department and the plaintiff’s counsel was informed that he would be contacted within a few days. This letter requested that he “forward any medical reports as soon as received and itemized special damages, so that we may discuss the matter with you.” On June 9, 1965, the defendant took a statement from the plaintiff which was not under oath.
*486Waiver is the intentional relinquishment of a known right. Jenkins v. Indemnity Ins. Co., 152 Conn. 249, 257, 205 A.2d 780. In the law of insurance, a breach of condition or warranty, out of which avoidance of the policy may be claimed, does not operate automatically to forfeit or avoid the policy, but sets in operation a right of choice. The insurer may elect either to continue or to terminate. The condition or warranty, the breach of which gives such right of avoidance, is subject to waiver either by express agreement or acts of the insurer from which waiver may be implied. Andover v. Hartford Accident & Indemnity Co., 153 Conn. 439, 444, 217 A.2d 60; MacKay v. Aetna Life Ins. Co., 118 Conn. 538, 547, 173 A. 783. Waiver may be implied from the circumstances if it is reasonable so to do. Breen v. Aetna Casualty & Surety Co., 153 Conn. 633, 644, 220 A.2d 254; DiFrancesco v. Zurich General Accident & Liability Ins. Co., 105 Conn. 162, 168, 134 A. 789. It appears to be well settled by all the later cases on this point that the insurer may, by waiver or estoppel, lose its right to defeat a recovery under a liability policy because of the insured’s failure to comply with the policy provisions as to notice of accident or claim or as to the forwarding of suit papers. The rationale of this holding obviously is that provisions with respect to notice and forwarding suit papers are inserted for the benefit of the insurer only and that it, therefore, must be deemed to have the right to waive compliance therewith. Note, 18 A.L.R. 2d 443, 487.
The conclusion that a party has waived a right is one of fact for the trier and not one which can be drawn by the court, unless, on the subordinate facts found, such a conclusion is required as a matter of law. The finding of facts by the trial court, the *487record of the first trial and the record in this case, amply support the conclusion of the trial court that the defendant waived the requirement of notice under oath. The defendant received the plaintiff’s notice before the expiration of the thirty-day period and could have required within the time limit that the notice be sworn to, but no such request was ever made by the defendant. It proceeded to investigate the claim, requested information from the plaintiff’s counsel as to medical reports and special damages, and defended on the grounds that the plaintiff exceeded her authority as an operator and that there was no contact with a hit and run vehicle. There was a hearing in the Superior Court and an appeal to this court without any mention of or reference to a failure of the plaintiff to give notice to the defendant under oath. The special defenses filed in both cases failed to mention such a claim. An examination of the entire transcript of the evidence in the first case indicates that no such claim was ever asserted. This claim was made for the first time in the second trial on October 29, 1969, some three years and five months after the defendant received the plaintiff’s written notice of claim. The defendant’s conduct is wholly inconsistent with any claim of lack of coverage by reason of the fact that the plaintiff's notice of claim was not under oath. The defendant accepted the notice as sufficient. Cahill v. Royal Ins. Co., 94 Conn. 118, 122, 108 A. 544. On the facts of this case the trial court's conclusion of waiver should not be disturbed.
When in the second trial almost three and one-half years after receiving notice of the plaintiff’s claim, the defendant offered evidence that the notice was not sworn to, this was a futile attempt to change its position. “[0]nce a right is waived, the waiver *488cannot be withdrawn even if subsequent events prove the right waived to have been more valuable than had been anticipated. DiFrancesco v. Zurich General Accident & Liability Ins. Co., 105 Conn. 162, 169, 134 A. 789; 56 Am. Jur., Waiver, § 24.” Jenkins v. Indemnity Ins. Co., 152 Conn. 249, 258, 205 A.2d 780. Having already waived its right to rely on a notice under oath, the defendant’s claim that the plaintiff was not covered by the policy was an attempt to change its position. But rights once waived cannot be regained by revoking the waiver. Hendsey v. Southern New England Telephone Co., 128 Conn. 132, 137, 20 A.2d 722; Lee v. Casualty Co., 90 Conn. 202, 208, 96 A. 952. The admission of evidence by the defendant whether with or without objection by the plaintiff could not alter the defendant’s waiver or affect it in any way.
Even in the case of misrepresentation of facts to the company by an insured, the question whether that conduct constituted a breach of a condition in the policy would be presented for the trial court. “The purpose of this provision is to protect the interests of the insurer, and any conduct of an assured . . . must have adversely affected its interest in some substantial and material way.” Rochon v. Preferred Accident Ins. Co., 118 Conn. 190, 198, 171 A. 429. The defendant has made no attempt to show that it was prejudiced in any way by the plaintiff’s failure to give it notice under oath.
In the present case the defendant tried unsuccessfully to establish that there was no contact between the car driven by the plaintiff and the hit-and-run vehicle and that the plaintiff exceeded her authority in the operation of the car. Having failed to establish either of these allegations contained in a special defense, it sought to do what it had failed *489to do three and one-half years previously. In sustaining such a course of conduct the majority is overlooking one of the closing paragraphs of our opinion in Frager v. Pennsylvania General Ins. Co., 155 Conn. 270, 279, 231 A.2d 531. I believe it warrants repetition. “Under No. 510 of the 1967 Public Acts, . . . the insurance commissioner is given broad powers of regulation over the terms and conditions of policies providing uninsured motorists coverage. These powers, coupled with the commissioner’s general powers over insurance companies doing business in Connecticut, would appear adequate to protect the public against possible abuses by insurers in connection with claims under provisions for uninsured motorists coverage, whether these abuses were to take the form of involving claimants in unwarranted litigation and procedural complexities or in delaying tactics intended to bring to bear on claimants the compulsive force of economic attrition.”
The judgment of the trial court should be sustained.
In this opinion Thim, J., concurred.
“by way of special defense The defendant makes the following claim: 1) That Sarah Frager was not covered by liability insurance; 2) That there was no coverage under this policy because of a violation of the policy in that Sarah Frager exceeded the permission granted to operate the vehicle covered by this policy; 3) In that Sarah Frager violated the Policy, Part IV, entitled 'Uninsured Motorist Portion/ in that she exceeded the permission granted to drive the vehicle covered by the policy and that a hit and run accident as defined under this coverage did not in fact occur; 4) In that Sarah Frager has made no application as provided under the policy for arbitration; 5) In that the question of whether Sarah Frager is an insured or not is not a proper question to be decided by an application directing arbitration, nor by an arbitrator, but is a question which should be decided by a Declaratory Judgment, hence, this application presents a moot question.”
“special defense 1. The plaintiff Sarah Frager was not covered by liability insurance. 2. That there was no coverage under this policy because of a violation of the policy in that Sarah Frager exceeded the permission granted to operate the vehicle covered by this policy. 3. In that Sarah Frager violated the Policy, Part IV, entitled ‘Uninsured Motorist Portion,’ in that she exceeded the permission granted to drive the vehicle covered by the policy and that a hit and run aeeident as defined under this coverage did not, in fact, oeeur and she did not follow the proper procedures as outlined by the policy as relates to hit and run accidents, for coverage. 4. In that Sarah Frager has made no formal application as provided in the policy for arbitration.”