Let’s look at the situation from the viewpoint of the overlapping Wheelchair User’s and Society’s Boundary Setting Paradigm. They overlap because in this case they are the same.

• The lines Communicate society’s rules for parking.
  Biker has a lack of Respect for the rules and violates it.
  The Wheelchair User Communicates society’s rules to the biker.
  Biker Communicates to wheelchair user to F$ck-off.

The Just Right Response for the wheelchair user is to now Communicate with the police or local security. They are in the most appropriate position to Enforce the parking rule.

What can be assumed about the Biker’s Boundary Setting Paradigm?

• Society’s parking rule doesn’t apply to me, or to my motorcycle.
  He communicates to the Wheelchair User his own rule of “Do not bother me with the rules of society” by using threatening language.
  The threat implies use of violence to Enforce the Biker’s behavioral rules.

Possible Conclusions to this situation:

If the Biker ends up moving his bike, then the Wheelchair User would have engaged in both Communication and Enforcement of society’s rules. If the police needed to be called, then he would have engaged in only Communication, and the police would have engaged in the final level Enforcement of the rules.

If the Biker doesn’t move his bike, it shows that he lacks Respect for the rules. Given the clear level of Communication, he has not misunderstood the rules.  Whether or not the Biker moves his bike is a direct function of his level of Respect for society’s rules and his Respect for the wishes of the Wheelchair User.