Daaaaaaamn. I know it was implied she had done something to him, but I didn't think it would be... that bad. Also, what's up with the husband? He's a freaking enabler! No way he wasn't aware of what was going on. And then, in recent chapters, when they were living in that trashed house, rather than helping his son, he just gets all butthurt and leaves.
Parents of the year, indeed.
@BCS I think it's possible due to his small size. Rather than a straight cliff, that place looks more like a slope. Maybe trees and bushes slowed down his fall and prevented any lasting damage?