The bats are individual tested and certified at some point in the post-season(and a team only allowed to use those bats). The problem is, I think this MAY only happen prior to Omaha, but I'm not positive.
The BBCOR bats last year had a metal "ring" in them that deadened them. You could remove the endcap, pull out the ring, and get alot better jump off the bat, and also alot better PING from the bat.
Nevermind the options you have with machining the barrels thinner for more trampoline effect, adding weight to the base of the handle, etc... There is ALOT of options in bat tampering.
That said, I'd be interested to know the exact policy on testing the bats before making any accusations...