I think it's easy to forget how deep of a history Marty and Raxx have.
It's not as simple as Marty convincing Chance to shove a medallion up his ass, and then Marty calls the cops. I don't think Marty ever started watching, or fucking with, Raxx with the intent for it to go as far as it has.
Marty has watched, and interacted with, plenty of internet retards without incident. In a way, Chance is the outlier to the whole sphere Marty cultivates, because of his explosive anger.
The fake contract would have probably been the end of Chance, if Dead Heather (Heather 2) hasn't shown up, and moved in, believing it was a real contract. After that, the cops were called, and he was swatter, because of his anger towards her, and so on. It's been a big game of retard ping-pong.