my bet is pills of some kind. they can usually taste it at the scene and see if its coke or not, or use that poweder identifier thing they got. pills are a lot harder to ID, theres a lot more of them that are used for different highs.
unless he was hitting a pipe, he was sniffing coke.. thats pretty much the first guess when u hear someone was caught in the bathroom with drugs
this guys sucks, he's a one trick pony as far as I'm concerned.