He wanted half of it after you loaned him $10, and he got the ticket with your money?! Hell no, he's fortunate you gave him $50 when you didn't have to at all! Let him be pissed.
Yeah, I'm kinda with this line of reasoning. You went WAY over being nice by giving him anything at all. To stare at that gift and ask, "Where's the rest of it?" shows a strong entitlement spirit. Has your brother been handed much of what he has? Is he employed? Educated? You didn't owe him anything, yet he feels you "owe" him half. This entitlement attitude has to be coming from somewhere. Is that his normal way of handling things? When you go out to dinner, does he expect you to pay for it? Dave