Sounds like your trainer might not know what's up :-/ Hackles aren't a bad thing, just a nervous system response. Everyone always thinks it's an aggressive response but it's not. He was just over stimulated it sounds like. :-/

And it's interesting that your trainer says he has to learn to heel first??? They are completely different behaviors in my book.

I hope things work out for you. I love taking classes with my pups.