"What they can't explain away was the laughing at the picketers and the conversing in single digit universal sign language.
At that point, their credibility was lost."
I'm sorry that happened, but put yourself in their shoes, they where thrust into an uncomfortable situation out of their control and it is human nature to defend ones self. They had no option but to do the flights once they arrived or face dismissal. Cargojet pilots are now aware of the situation and have, as far as I know, universally refused any more of these flights. Of course that won't stop management pilots from being forced into this work.