Oh, Bart. And Max. That first moment up there really does a good job of showing him as human and flawed. And more like Impulse than he knows, I think. Simply running away from your problems isn't something you tend to put a whole lot of thought into, after all.
Bart's got a pretty classic reaction to leaving someone you love in the second scan. Shielding all the hurt with anger is pretty common, especially with kids and teens. It just seems easier to deal with. But then Max breaks through Bart's defenses. Awwwwww.