If he gave that money to a native charity like a scholarship fund, no one could call him an asshole. The bet was that he would give the money to a charity SHE picked out. If he gave it out of the goodness of his heart, it'd be a great PR move.
Plus, didn't the DNA test come back with native genes? The bet wasn't that she would be allowed membership into any specific tribe, just that she had native DNA. Which... she did.
I'm not following this super closely, but it really seems like she won the bet. Because it wasn't a bet of "I'm WBCN." It was a bet of, "Hey you need to quit saying racist shit. I've got native blood and it's offensive. Don't be calling people "Pocahontas" and shit."
I don't like that she did it either- read the thread. As soon as I found out about it I called her out and made all kinds of fun of her. But she did win this extremely white people nonsense bet, and even if she hadn't, it would be a great PR move to give an amount of money that we know Trump considers "small" to some needy kids to show how NOT butthurt he is.
Warren's DNA was not matched to any specific native American bloodline. There were minute matches with three blood strains from Central and South America. That "match" was 1/1024, so if Trump were to honor the spirit of the bet he would pay Warren about 1,000 Bolivars.