Does the PBUC manual describe every mechanic needed to handle every possible play? How about the CCA? Red book?
6.06a It's in the rules because administrators want to prevent batters from gaining an illegal advantage. It's a tough call to make. At the MLB level the pitches and players are incredibly fast, making this call truly difficult. That's why when it is enforced the call makes SportsCenter...when it's not enforced it also makes SportsCenter too.
Life goes on.