Pilots don't just leave their jobs for no reason especially at a time when it's not easy to get another job but it's hard to stay where your not wanted. Nobody wants to go to work and be miserable every day.
From what I've read on this thread and heard elsewhere the new regime wanted the old Heliair guys out and made life miserable for them, changing their jobs, taking away their responsibilities, threatening to fire them for some misdemeanour etc etc.
If what's been said on this thread about the new MD's mega ego is even half true it's not surprising he'd want this high profile guy out of the way.