I think I read that somewhere. Prior to joining the squad one of the T&T players asked him if he had 'Trini blood' in him and obviously the answer was yes. I think he also realized an England cap wasn't in his future.
That is definitely true, because if an English cap was in his future, he would have played there (where he was born).
Meanwhile, Kevin Pietersen knew how good he was (good enough to get an English cap) and that it was a much more high profile spot than the South African team, which is why he made his move.
I also read somewhere that Burchall is the first white player on Trinidad's roster in 30 years.