ALSO re: what buck did in mother's day, you can tell that his choice to give himself (his self) up for eddie and chris is calculated and not a mindless self-sacrifice because buck is NOT the type to force himself to be the sacrificial lamb for eddie if he knows it would make a situation worse. we saw this in brawl in cell block 911, where buck was willing to leave eddie alone (even if he didn't like it) if he understood that THAT was the best way of maximizing their safety. buck made the decision in that basement stone cold knowing that it was the most logical thing to do. doesn't make it any less of a sacrifice, or any less revealing of how important the diaz boys are to him, but it WAS a canny decision.
also, notably, in both cases buck only lost his shit and ran out to save eddie, throwing himself into possible danger, when he hears a gunshot. once eddie's life is actively in danger, all bets are off.
