@Istvan90623 Dude, he was 17 when he died. He's 15 now. He's never been an adult, regardless of how long his memory is. And his body is that of a kid, like you said. The mind is basically a mess of chemicals, which is why being drunk is a thing. It's also why going through puberty sucks so much, since hormones mess with your mind.
Edit: sorry forgot something. He knows only Gizel could have messed with the cart; she's the only one he told about the ore. He also knows she's smart enough to realize the situation a broken down cart would cause. Her intentions don't matter, the fact that she knowingly put him in mortal danger does. And Abel knows that.
@Hollow7F See above, he's not an adult in any way. You expect a kid to somehow fix his sister being raised by mad people, in just 3 days?
Edit: Sorry, got his age slightly wrong. He's 16, by mere days.