Biff blinked, but made sure not to move. What the hell? Why was he thinking of a music hall? His "happy place" had always been him out on the field playing football, having a bunch of hot girls nearby cheering for him and him showing off to them. But that wasn't what he was thinking of right now. He saw himself playing a violin, of all things, up on a stage. He was playing it beautifully, of course, but what the hell? He didn't even know how to play! Why would he think of something like this?
As it turned out, Jordan and Jack didn't have too much of a problem during the whole thing, but Biff and Heather did. After their guarding duty test was over, Marty commented on that, that a few times it looked like they would make a reaction, but complimented them that they had successfully resisted doing so.
Biff walked over to Heather, relieved that it was over, but he certainly had a few things to discuss with her.