specially concurring:
I concur in the decision of the majority. I write separately, however, to express my disagreement with Western Bonded Products v. Industrial Comm’n, 132 Ariz. 526, 647 P.2d 657 (App.1982). Western Bonded states, as the majority points out, that:
Even a logical interpretation of events surrounding the industrial incident and claimant’s ensuing complaints, when *498made by a layman, is no more than speculation.
Id. at 527, 647 P.2d at 658.
I cannot agree with so broad a statement of the law.
The court has not spoken with one voice on this point. Western Bonded clashes with two earlier decisions by this court, State Compensation Fund v. Mohrman, 18 Ariz.App. 447, 503 P.2d 405 (1972), and Estes Corp. v. Industrial Comm’n, 23 Ariz.App. 370, 533 P.2d 678 (1975). The supreme court has not resolved the conflict.
New would disagree that an expert is usually required to define the medical consequences of a workplace accident. Western Bonded errs, however, in my view by exalting the usual into an axiom without exceptions. Mohrman and Estes recognize that, in some cases, adequate causal inferences may be drawn from lay and circumstantial evidence. Larson favors this more flexible approach—see 2B A. Larson, Workmen’s Compensation Law § 79.51(c) (1988)—and I believe it the correct one under Arizona law.
In this case, however, lay testimony and circumstantial evidence were insufficient to establish whether claimant’s left shoulder impingement in 1988 resulted from his original industrial injury or from an unrelated, intervening cause. The claimant failed to offer a supporting opinion on this issue from Dr. Zachary or any other expert. Thus, I concur in the majority’s decision to affirm.