Oh my. Biff is so used to having nothing to say during those strategy sessions that he’s completely missed his cue and forgot his line on top of it. And this would have been his big chance, too! The situation doesn’t often call for ideas so stupid the script could reasonably assign them to Biff.
Fortunately, the Professor is unperturbed – he just carries on with the plan, ignoring all the unspoken suggestions of the others in favour of going with Biff’s idea, even if it remains similarly unspoken. Actually, he even prefers it this way – agreeing to Biff’s idea would have made him look rather stupid, if it had been said out loud. And Biff is just happy somebody tells him what to do. He’s good at doing stuff people tell him to do.
More on Monday.