I don't fault the guy for quitting his job in such style, but it wasn't exactly wise. Brave to be sure, but this is going to follow him for a good while yet. Not only is the improper use of airplane emergency equipment (such as emergency chutes) illegal and punishable by a VERY hefty fine, but he's essentially locked himself out of any future job in any airline in the US, and indeed, in most nations. If anyone calls to check his references, they'll know about this incident.
If you are an employer, regardless of what industry you are in, you will think twice about hiring this guy. The only hope is for this guy to exploit his bravado and try to get a gig as an "EXTREME" radio/television personality. Or he could try to write a book about this experience and the stress of working as an airline steward.
I dunno - I bet he's going to regret doing this. It's one thing to say "stuff you" to a boss - but another thing entirely to delay a flight, use aircraft equipment improperly and verbally assault passengers. He's facing up to 7 years in jail. I hope he doesn't serve any time, (well, maybe a week or two) but he really should have thought things through more.