The Texas Supreme Court has applied several arcane, and not easliy explanable rules to attorney fees.  In this particular case arising from bull semen sales, the applied rules are more fully expanded upon and fleshed out in this Law Com article.

 "Barker, the high court also for the first time applied to attorney fees the "presumptive harm" rule that it annunciated in 2000’s Crown Life Insurance Co. v. Casteel and subsequent cases. The court concluded in Barker that an appellate court will presume harm and must reverse the attorney fees awarded unless it can be reasonably certain that the jury’s fee award was not significantly affected by the error in the damages award. "