Probably not a true story anyway. But interesting

Whatever, you cheap jerk.

Nigga if someone complained bout my tip I'd take my 5 bucks back and make it rain on his mom while she strips for me. Ungrateful lil shit.

"The waiter had a strange feeling on his face after the tip." This would indicate that the waiter physically feels something on his face. The word you're looking for instead of "feeling" is either "look" or "expression." Even then, the sentence still sounds clunky. Also, as charitable as Bill Gates is I doubt he'd leave such a small gratuity, but I get the moral of the story. I'm just someone with too much time to nitpick.

Wait, but that's just an excuse to stiff her out of a tip! Yes he's the son of a woodcutter, but what does that have to do with anything???

His daughter looks like Rachael Leigh Cook

Firstly, maybe he tipped her $5 but paid off the rest of her tuition fees..
Secondly, what does Rachel Leigh Cook's picture gotta do with the story...

"the waiter had a strange feeling on his face"