Our trainers are behaviourists too.
We did manage to get Logan walking around the dog he had taken a dislike to with no problems as we were taken to 1 side to work on. The difference there that we were expecting it so was easier to deal with. In "real life" they happen so few and far between that they catch you unawares
He passed gold in January and we haven't been back at training since because my girl is in the gold class so was just taking her, but I'm going to alternate weeks and take him back and go back to basics with him so that any idea's of grandeur he may be getting will hopefully get nipped in the bud.