Apparently Kimberly found some drug paraphernalia and told people, I think Bischoff included, that the stuff belnoged to wrestling Mother Theresa - Tammy Sytch. As we know Steiner cared about two things - his freaks and his peaks - and this apparently set him off. This is the promo that followed those events and preceded their fight.
And here all this time I thought it was just roid rage.