Bell escalated this from the moment he got involved
What happened before Bell 'got involved'?
Did he involve himself or did they involve themselves on Bell?
Do you know what happened before the video begins?
True, I don't know what happened before. I do know some basics about self defense under the law. Also that avoiding fights means you don't risk getting arrested or prosecuted, because District Attorneys don't care how justified a person feels about decking someone. Those kids are citizens with rights too. A bunch of kids being noisy outside a mall is a nuisance, not a threat to life or limb. He and has family could have gone back inside and called security or management, or waited a few minutes until those kids parents showed up, moved on or calmed down. Or maybe, just walked through them to their car and left.
No matter what anyone wants to say, he compromised his mantle of innocence by how he acted. He was the adult, they were minors, the higher standard of care is on him, not the kids. There's also disparity of force in that he's weighs at least hundred pounds heavier than a eleven year old girl. He knocked her out into a metal pole, when there was no threat justifying that level of force. Self defense is proportional to the threat, and noisy 11 and 12 year olds aren't much of a threat under the law.
A lot of people on these threads have a macho view of self defense that does not match reality under the law.