I will be horrified if this guy isn't fired. He clearly does not possess the judgment, self-control, and sense of sportsmanship one needs to represent an NFL team.
I know plenty of dirty stuff happens every day and most of it isn't caught on video. But if you DO happen to catch it, it needs to be swiftly and severely punished.
What kind of message does keeping him send? To the fans? To the players? To anyone else contemplating playing a little dirty?
He could have ended that kid's career, not to mention left him with a life of pain, disability, and medical bills. Carroll signed on to take hits on the field within the rules of the NFL. He never agreed to have to watch out for the sideline as well.