if they had been native americans instead of black, i think that would be rascist too, both have been subject to 'savage' charicatures in media. its the historical negative portrayals that have to be taken into account.
I think sometimes people tend to take things a bit too far. Would the episode still be racist if only Lutan were black?
Do we only give 'savage' roles to white actors now because if we give it to a minority it'll be called a caricature and the producers will be accused of racism? Of course, the producers will also be accused of racism if they refuse to give 'savage' roles to minority actors.
White people (I'm one) have said and done alot of shitty things over the centuries but don't penalize minority actors because of it. I'm for giving any role to the actor best suited to play it.