i'm going to go out on a limb and say if the coach looked something up, did not further argue it or otherwise cause play to stop, why keep him or her from learning something (or learning what they originally thought was wrong
)? As one of the sayings I've learned on here goes, why look for trouble that doesn't exist?
I've never seen any rule in basketball, softball, soccer, or volleyball that precludes a coach from reading a rulebook during the game. That said, I would 100% agree that if a coach brings it out on the field or tries to use it to show up an official, that needs to be dealt with immediately.