I think it's pretty obvious what happened at this point.
The whole room hated McDavid because he was so arrogant about how awesome his new counter tops were. Drai obviously disagreed and decided to take matters into his own hands. It turns out the counter tops were as awesome as McDavid kept saying though, so Drai came out on the losing end.
Drai, in his embarrassment over losing a fight to a counter top, decided to start a rumour that it was in fact Nurse who hit him(which Nurse agreed to since he also hated McDavid) to save face.
This upset McDavid, so he leaked the actual story to Gregor in hopes to get a shout out for his awesome new counter tops.