If he'd had a viable, regular, AB career beckoning he wouldn't have jumped on the plane. He was born in NZ, raised there, played his rugby there, represented them at U20 and has lived his whole life there. He may have an affinity for Eng through his parents, but with that background he'd be a very odd fish if his preference hadn't been for black over white.
With the rules as they are and the way players move now I get a lot less exercised by it all. But of course I'd much prefer to see home grown talent representing us.
At least he has some proper links through his parents. I see him as more opportunistic than outright mercenary.