Bad day at Nebo's class :(

Sounds like he's making some progress:) I hope he does good at class!

I would just get him used to men as much as possible. Like you sadi take treats everywhere w/ you & have men give them to Nebo. But NEVER give him any treats when he is acting up. let him calm down & maybe even obey a command then praise him.
Maybe their apperance (hats or strange walk) gets him frantic but to pass cgc he needs to learn to accept it all. Don't have much time now maybe this was already posted I did not read all the replies. Good luck