Sorry mate!
As a pom who went to oz to get my professional licences, worked over there, got great experience, and generally had a great time, I came back and converted my ATPL to the UK one( at a cost of about £11,000 )
Yes, I got one of those UK jobs and I know quite a few ozzies and kiwi's who also did,
to my knowledge none of them have work permits, all of them are on British (or EU) passports.
Just 'cause they have a different accent, doesn't meant they can't work and live here!
They get the easyjet jobs because they have the experience and are pretty good pilots, learn from them and don't slag them off!
As to those going back, can you blame them after the winter we've had this year!