The difference between this incident and others is he got caught on video.
He confronts KG in the back, it gets covered up. KG and Melo deny it (no snitching) and everyone moves on.
You get caught on camera stalking KG by the player bus, then the league has NO choice but to suspend him. It's 100% about image, and the suspension comes down to conduct that harms the NBA.
Whether there was a fight or not, the NBA has to clamp down on this stuff. If you're the NBA, you look at this as a dodged bullet. What IF KG and Melo had gotten into a fight? What IF one of them gets injured and it gets plastered all over the Media?
Melo walked right into the trap, and none of his team mates were smart enough to keep him out of it.
Failure by Melo, failure by Woodson, and a disappointment by his team mates.