dissenting.
{¶ 48} I dissent. In Dr. Trent Sickles’s deposition, there were several unequivocal statements that he did not intend to offer any opinions on causation, a necessary element of a medical-malpractice claim:
{¶ 49} “Q: Do you intend to render any opinions concerning the treatment that she may or may not have undergone had a diagnosis been made in June of 1999?
O50}“A: No.
{¶ 51} “Q: Do you intend to render any opinions as to the effect of the alleged three-year delay upon the patient’s treatment or course?
{¶ 52} “A: No.
(¶ 53} “Q: Do you intend to render any causation opinions in this case?
{¶ 54} “A: No.”
{¶ 55} “Q: What is your understanding of Miss Pettiford’s subsequent diagnosis in 2002? WThat was she diagnosed with?
{¶ 56} “A: My general recollection is lung cancer, but I can’t even recall the specifics, because after I looked at the records I pretty much determined that I couldn’t testify or give any opinions about causation so I haven’t looked at that since a year-and-a-half ago.”
{¶ 57} Thereafter, the affidavit of Dr. Sickles was filed on February 6, 2008, the same day the plaintiff filed her memorandum contra defendant’s motion for summary judgment and just six days before the judgment of the trial court was rendered. The affidavit, in completely contradicting the prior statements made in the deposition, stated, “I further agree to testify as an expert for the Plaintiff, Barbara Pettiford regarding damages she has suffered as a direct and proximate result of Dr. Aggarwal’s negligence.”
{¶ 58} Nothing in the record even remotely suggests that Dr. Sickles did not initially want to testify as to causation because apparently, physicians are often reluctant to testify until they know their own medical-malpractice coverage will not be affected. In fact, the record is completely void of any explanation as to why Dr. Sickles changed his testimony in an affidavit submitted the same day as the plaintiffs memorandum in opposition to summary judgment.
{¶ 59} Most differences between a witness’s affidavit and deposition are a matter of degree and details rather than direct contradiction as here. If the differences fit into a category of variations on a theme, this is ground for impeachment and not a vitiation of the later filed document. If, on the other hand, the subsequent affidavit is a clear contradiction and indeed a new expert *715opinion involving material issues in the suit, without explanation, the affidavit must be disregarded and should not defeat the motion for summary judgment.
{¶ 60} The majority, acknowledging that contradictions exist between the deposition of Dr. Sickles and his subsequent affidavit, concludes that Byrd v. Smith, 110 Ohio St.3d 24, 2006-Ohio-3455, 850 N.E.2d 47, does not control in this case because Byrd is inapplicable to nonparty witnesses. I do not agree with such a narrow reading of Byrd. Throughout the Byrd opinion, the Supreme Court never conclusively holds that it applies only to parties to the litigation.
{¶ 61} Although I would agree that Byrd should not apply to some nonparty lay witnesses, I do not agree with the majority that it should not apply to a retained expert witness. In Clemmons v. Yaezell (Dec. 29, 1988), Montgomery App. No. 11132, 1988 WL 142397, at * 5-6, we explained the difference between a party witness and a nonparty witness:
{¶ 62} “The party witness generally has the benefit of counsel to protect him from inadvertent misstatements. Therefore, when a party witness has given certain detrimental answers in a deposition, but subsequently, upon advice of counsel, sets forth averments in an affidavit in order to ‘clarify’ or ‘correct’ what was said in the deposition, the subsequent affidavit should be disregarded. The affidavit is being used as a self-serving device to avoid damaging admissions made by the party witness during his deposition.
{¶ 63} “However, in a situation where a non-party witness has given certain testimony in a deposition and then given contradictory averments in a subsequent affidavit, the same factors are not present. Neither the litigant nor his attorney can prevent the non-party witness from deliberately or inadvertently misstating facts during the deposition, at least not to the same extent that the litigant as witness can be protected from inadvertent misstatements during a deposition.” (Emphasis added.)
{¶ 64} When the deposition testimony of a nonparty witness involves a lay witness’s recall of factual events and circumstances, I agree that Byrd may not apply. However, the issue at bar involves new “opinions” of an expert witness, retained by appellant, for his testimony. In fact, expert witnesses are regulated by more demanding and restrictive discovery rules. In this context, a retained expert witness is more akin to the party in terms of management by counsel and providing testimony favorable to the claims. The issue isn’t one of memory or recall, it is one of the forming and subsequent contradictory changing of opinions. Here, the affidavit of Dr. Sickles is being used in the same way prohibited by Clemmons: as a self-serving device to avoid damaging testimony given during that deposition. Only after the defendant had filed his motion for summary judgment, stating that the plaintiff had not adduced any evidence as to causation *716and damages, did the defendant obtain an eleventh-hour affidavit from Dr. Sickles.
{¶ 65} In Byrd, the Supreme Court ruled that a three-step analysis must be followed in determining whether to disregard an affidavit inconsistent with or contradictory to prior deposition testimony when ruling on a motion for summary judgment. First, the trial court must consider whether the affidavit contradicts or merely supplements the deposition.
{¶ 66} Here, as noted above, the attestation in Dr. Sickles’s last-minute affidavit is a complete contradiction of the testimony in his deposition. In Dr. Sickles’s deposition, he unequivocally indicated that he would not be rendering any opinions as to causation. He stated that since he couldn’t give any opinions on causation, he hadn’t looked at the plaintiffs file for a year and a half. Furthermore, he agreed that if he were to change his opinion, he would contact the defendant so the defendant could conduct an additional deposition. Thereafter, Dr. Sickles submitted an affidavit that stated: “I further agree to testify as an expert for the Plaintiff, Barbara Pettiford regarding damages she has suffered as a direct and proximate result of Dr. Aggarwal’s negligence.”
{¶ 67} The second step of the Byrd analysis requires the trial court to consider whether an affidavit appears to be inconsistent with a deposition. If so, the court must look to any explanation for the inconsistency.
{¶ 68} Here, there is nothing in the record that provides an explanation for the inconsistency. Dr. Sickles testified that he had no opinion as to causation at his deposition on November 14, 2007. He also agreed that if he were to modify, alter, change, amend, for any additional opinions or modify the ones given the day of the deposition, he would contact plaintiffs counsel so an additional deposition could be held. After the defendant moved for summary judgment on January 30, 2008, the plaintiff filed Dr. Sickles’s contradictory affidavit on February 6, 2008, the same day the memorandum contra defendant’s motion for summary judgment was filed.
{¶ 69} The final step of the Byrd analysis requires that “[ojrdinarily, under [Civ.R.] 56(C), when an affidavit is inconsistent with affiant’s prior deposition testimony as to material facts and the affidavit neither suggests affiant was confused at the deposition nor offers a reason for the contradictions in her prior testimony, the affidavit does not create a genuine issue of fact which would preclude summary judgment.” Byrd, 110 Ohio St.3d at 30, 850 N.E.2d 47. The court thereby suggests that, in this third step, a trial court must examine the depositions and affidavits to determine if there is a valid reason for the inconsistencies. If there is no valid reason for the inconsistencies, the court held, “an affidavit of a party opposing summary judgment that contradicts former deposi*717tion testimony of that party may not, without sufficient explanation, create a genuine issue of material fact to defeat a motion for summary judgment.” Id.
{¶ 70} An unsubstantiated assertion is not sufficient to overcome the effect of prior unequivocal testimony under oath. Dr. Sickles had access to the pertinent information at the time of his earlier testimony. He chose not to use the pertinent information because, in his words, “I can’t even recall the specifics, because after I looked at the records I pretty much determined that I couldn’t testify or give any opinions about causation so I haven’t looked at that since a year-and-a-half ago.” There is no indication that his opinion on causation is based on newly discovered evidence, nor does the earlier testimony suggest any confusion which the affidavit seeks to explain. Dr. Sickles does not give us a credible explanation based upon further review, careful study, or even fear of loss of insurance, as the separate concurring opinion suggests.
{¶ 71} I would hold that the Byrd analysis applies in this case, where an expert witness — hired by the plaintiff — contradicts his unequivocal sworn deposition testimony with an unsubstantiated, and last minute, affidavit. Accordingly, I would affirm the trial court’s grant of summary judgment.