dissenting.
I must respectfully dissent to the granting of Wasserman’s petition for a writ of mandamus.
Wasserman labors under a “heavy burden” in attacking Judge Black’s ruling denying the motion to disqualify Fulcher from representing any of his clients in the original suit filed by Smith, McKinley, and Brooke. See Johnson v. Fourth Court of Appeals, 700 S.W.2d *570916, 917 (Tex.1985). He must show that the court reached a decision so arbitrary and unreasonable as to constitute a clear and prejudicial error of law. See id. Furthermore, he must establish that, under the circumstances of the case, the facts and law permitted Judge Black to make but one decision, i.e., to disqualify Fulcher under Rule 1.09.1 See id.; Tex.Disciplinaey R.PROF.Conduct 1.09 (1994), reprinted in Tex.Gov’t Code Ann., tit. 2, subtit. G. app. (Vernon Supp.1995) (State Bar Rules art. X, § 9). This court cannot substitute its judgment on factual matters committed to the trial court’s discretion.2 See Walker v. Packer, 827 S.W.2d 833, 839 (Tex.1992). We can, however, review the trial court’s application of the legal principles controlling its ruling. See id. at 840.
Because what record we do have before us conclusively shows, as of the time of the hearing on the motion to disqualify, that Fulcher was not then representing any clients in an action against Wasserman, I would hold that the trial court did not clearly abuse its discretion when it concluded that Fulcher was not disqualified by Rule 1.09.
RULE 1.09
At the heart of the controversy is the correct interpretation of Rule 1.09. Tex.DisCIPLINARY R.PROF.CONDUCT 1.09 (1994). Its plain language prohibits a lawyer from representing another person in a matter “adverse to the former client.” Id. 1.09(a). Interpretive comments to the rule clearly contemplate that for the rule to apply the representation of a second client must involve a matter “against” the former client. Id. 1.09 emts. 1, 2, 3, 4. Therefore, for Rule 1.09 to apply, Fulcher must be representing another client in a matter “adverse” to Wasserman and, to be adverse, that matter must be “against” Wasserman.
SUIT BY SMITH, MCKINLEY, AND BROOKE
When the court heard and denied Wasser-man’s motion to disqualify, Fulcher was then representing the City of Teague, Sartor, Shinn, Herrington, and Wylie, as defendants and counter-plaintiffs, in the original suit filed by Smith, McKinley, and Brooke. The court had previously granted Fulcher’s unopposed motion to withdraw as Wasserman’s attorney, and thus Fulcher was no longer representing him as a defendant or counter-plaintiff in the original suit. W.R. Malone was apparently representing Wasserman in his capacity as a defendant and counter-plaintiff in the original suit. Therefore, at the time of the hearing, all of Fulcher’s clients (City, Sartor, Shinn, Herrington, and Wylie) were in an adverse position to Smith, McKinley, and Brooke. Wasserman was also in an adverse position to Smith, McKinley, and Brooke, but he was being represented by Malone.
WASSERMAN’S SUIT AGAINST CITY AND SARTOR
Two of Fulcher’s clients (City and Sartor) were in an adverse position to Wasserman at the time of the hearing on the motion to disqualify because they are cross-defendants in Wasserman’s cross-claim based on wrongful termination and a claim for indemnity. But, at the time of the hearing, Kenneth R. Stein was representing the City and Sartor in their capacities as cross-defendants on Wasserman’s cross-claim. Thus, Stein — not Fulcher — was then representing the City and Sartor in a matter adverse to Wasserman.
SEPARATE TRIALS
Moreover, prior to the hearing on the motion to disqualify, the trial court ordered that the suit by Smith, McKinley, and Brooke against the City, Sartor, Shinn, Herrington, Wylie, and Wasserman be tried separately from Wasserman’s cross-claim against the City and Sartor. Accordingly, when the trial occurs on the original suit, the City, Sartor, Shinn, Herrington, and Wylie will be repre*571sented by Fulcher, and Wasserman presumably will be represented by Malone. In Was-serman's separate trial on his cross-claim, Stein will be representing the City and Sartor, and Wasserman will be represented by Malone.3
RELIEF SOUGHT BY WASSERMAN
Wasserman seeks a writ of mandamus directing Judge Black to withdraw his order denying the motion to disqualify and directing him to enter an order disqualifying Ful-cher from representing any litigant. He is thus seeking to have Fulcher disqualified from representing the City, Sartor, Shinn, Herrington, and Wylie in their capacities as defendants and counter-plaintiffs in the original suit brought by Smith, McKinley, and Brooke. Wasserman asserts by affidavit that he never consented to Fulcher’s continued representation of any defendants in the original suit. He contends that the trial court should have disqualified Fulcher under Rule 1.09 because “it is to be expected that Mr. Fulcher will attempt to place all blame for any damages suffered by [Smith, McKinley, and Brooke] upon [Wasserman] rather than his remaining clients, and to aid Mr. Stein, now apparently lead counsel for the City and Sartor[,] in similar efforts in the separate trial of [Wasserman’s] cross-action.” He further argues that to permit Fulcher’s continued participation in the case will “bring further obloquy upon the legal profession by the actuality, and certainly the appearance, of impropriety.”
Rule 1.09 is the only ground asserted by Wasserman in his motion to disqualify Ful-cher. He cannot show from the record that, at the time of the hearing on the motion, Fulcher was representing another person in any matter adverse to him (Wasserman), which is a threshold requirement for the rule’s application. See Tex.DisciplinaRY R.PROf.Conduct 1.09 (1994). Setting aside his failure of proof in that regard, he also has not demonstrated from the record that Judge Black could have made but one decision on a factual matter committed to his discretion— i.e., whether a reasonable probability then existed that Fulcher’s representation of his clients in the original suit will involve a violation of Rule 1.05. See id. 1.05 (1991), 1.09(a)(2) (1994). “Whether such a reasonable probability exists in any given case will be a question of fact.” Id. 1.09 cmt. 4 (1994). Nor has he demonstrated from the record that at the time of the hearing Fulcher was representing another person in the same or a substantially related matter. See id. 1.09(a)(3) (1994). In fact, the record conclusively establishes the contrary of that proposition.
Wasserman’s problem is that he is seeking to have Fulcher disqualified under Rule 1.09 even though he is not representing the City, Sartor, Shinn, Herrington or Wylie in any matter adverse to him (Wasserman). The City and Sartor are involved in the litigation in two separate legal capacities: they are defendants and counter-plaintiffs in the suit by Smith, McKinley, and Brooke, and they are cross-defendants in Wasserman’s cross-claim. The City and Sartor are clearly entitled to be represented by different counsel in each capacity.
This is not say, however, that Fulcher does not owe Wasserman any continuing duties under the disciplinary rules. In fact, Ful-cher is somewhat hemmed in by having represented Wasserman. First, he cannot knowingly use or divulge any confidential information obtained from Wasserman to Wasserman’s disadvantage. See id. 1.05(b)(3) (1991). Consequently, in his representation of the City, Sartor, Shinn, Herring-ton, and Wylie in the original suit, Fulcher cannot disclose or use any confidential information obtained from Wasserman to Wasser-man’s disadvantage. Nor can he divulge any such information to Stein, who is represent*572ing the City and Sartor in their capacities as cross-defendants in Wasserman’s cross-claim.
Moreover, during the trial of the suit by Smith, McKinley, and Brooke, Fulcher cannot take any action on behalf of his clients that would be in any way adverse to Wasser-man. See id. 1.06 (1991). This precludes him, for example, from pursuing a trial strategy that would in any way shift blame to Wasserman for any of the acts alleged against Fulcher’s clients in the suit by Smith, McKinley, and Brooke. His continuing duty of loyalty to Wasserman, as a former client, not only precludes Fulcher from recommending or filing any cross-claim against Wasser-man on behalf of his clients but prevents him from engaging in any adverse cross-examination of Wasserman. Finally, Fulcher cannot assist Stein in any way in the preparation for trial or defense of the City and Sartor in Wasserman’s cross-claim.
Thus, Fulcher can only represent his clients in the original suit in a way that accommodates his continuing duty to Was-serman under the disciplinary rules. A potential possible conflict between the representation of his clients in the original suit and his continuing duty to Wasserman does not preclude Fulcher from continuing to represent his clients in a matter that is not directly adverse to Wasserman. See id. 1.06 cmt. 4 (1991). It is for the City, Sartor, Shinn, Herrington, and Wylie — not Wasser-man — to decide whether to proceed with an attorney who must accommodate Wasser-man’s continuing interests.4 See id.
Wasserman contends, in effect, that the . limitations Fulcher has with respect to his clients disqualifies him from representing them in the trial of a matter that is no way adverse to him (Wasserman). As already noted, however, that decision lies with Ful-cher’s clients, not with Wasserman. More than Wasserman’s interests are implicated by the intricate facts. Any attempt to disqualify Fulcher is of substantial importance to his clients, and their interests must be considered as well. See id. 1.09 cmt. 9 (1994).
Accordingly, I would deny the petition for a writ of mandamus. Wasserman has not demonstrated from the record that Judge Black could have reached only one decision under the law and facts and that the decision he reached is so arbitrary and unreasonable as to constitute a clear and prejudicial error of law. See Johnson, 700 S.W.2d at 917.
. Wasserman based his motion to disqualify solely on Rule 1.09.
. Wasserman's counsel states in an affidavit that Judge Black denied the motion without hearing any evidence, a statement that is not disputed in the record. Under the circumstances, Wasser-man must demonstrate a clear abuse of discretion from the record before us. See Barnes v. Whittington, 751 S.W.2d 493, 495 (Tex.1988).
. At oral argument on the petition for a writ of mandamus, Fulcher stated that he will not participate in any trial on Wasserman's cross-claim. As noted in the opinion, however, the City and Sartor are engaged in litigation in two separate legal capacities, one as defendants and counter-plaintiffs in the original suit by Smith, McKinley, and Brooke and also as cross-defendants in Was-serman’s cross-claim. To make his role as counsel distinctive and crystal clear, Fulcher should consider formally withdrawing as attorney for the City and Sartor in their capacities as cross-defendants in Wasserman’s cross-claim.
. Under the circumstances, Fulcher should clearly and fully disclose these limitations on his representation to the City, Sartor, Shinn, Herring-ton, and Wylie so they can decide whether to obtain different counsel. See Tex.Disciplinary R.Prof.Conduct 1.09 cmt. 9 (1994).