Saint George was Palestinian, of Greek and Roman heritage, so go figure.The mistake made was when Rowling said anything other than "she's the right person for the role" because that's all that needed to be said end of story. Also I wonder how many if those so het up about it were going to get down to the West End to see it.
I saw the Holy Grail in London and King Arthur was Asian ( Uk usage) and it was a bloody good show didn't ruin either my childhood or the original. But that wasn't the craziest thing they'd done they'd even had an Australian play him, mmmmaaaddddness. I also saw one with swearing Muppets, absolute genius and didn't ruin my childhood.
Now I come to think of it they really can't the nationality right on any of the British heroes. Robin Hood is either a Yank or an Aussie, William Wallace an alcoholic anti-Semitic Aussie and Richard the Lionheart a F***ing Scotsman (and a straight one at that). I also fairly sure they've never had a Welshman play King Arthur.
Dumb people be dumb.