Let's be honest, from this video alone you really can't be certain what happened between Izzy and this guy. They both have aggressive body language are talking shit.
That being said, the fact that Israel is standing at his car and appears to be trying to leave indicates that the other dude is probably the aggressor. You can see him take 2 steps towards Israel right at the beginning of the video seemingly trying to intimidate acting like he's going to swing any moment while talking shit.
The fact that you think this is normal or acceptable behavior to do someone in public (whether they're a douchey fighter or not) is pretty fucked up. This guy actually did these actions in real life, not on a goofy internet forum.
I highly doubt you would go around on the streets causing altercations with pro fighters that can beat the shit out you purely because "people call out douchebags".