Here's a link to the full opinion.
http://www.courtinfo.ca.gov/opinions...ts/S119575.PDF
The beanball in question allegedly was in retaliation for a hit-by-pitch in the previous half inning. The only issues were the liability of the pitcher's college to the hit batter. I'd say the core quote is:
It is true that intentionally throwing at a batter is forbidden by the rules of baseball. (See, e.g., Off. Rules of Major League Baseball, rule 8.02(d)). But even when a participant’s conduct violates a rule of the game and may subject the violator to internal sanctions prescribed by the sport itself, imposition of
legal liability for such conduct might well alter fundamentally the nature of the sport by deterring participants from vigorously engaging in activity that falls close to, but on the permissible side of, a prescribed rule. It is one thing for an umpire to punish a pitcher who hits a batter by ejecting him from the game, or for a league to suspend the pitcher; it is quite another for tort law to chill any pitcher from throwing inside, i.e., close to the batter’s body—a permissible and essential part of the sport—for fear of a suit over an errant pitch. For better or worse, being intentionally thrown at is a fundamental part and inherent risk of the sport of baseball. It is not the function of tort law to police such conduct.