All this 'traffic jam,' 'double yellow line,' stuff is completely irrelevant. You use pepper spray in SELF DEFENSE. The bicyclist bears the burden of proof that use of pepper spray was justified in this case, plain and simple. I don't think being inconvenienced in traffic is enough; but certainly if he was harassed or near-assaulted by vehicle(s) then that is another matter.
Some he-said she-said testimony, no doubt. I feel bad for the biker, because it sounds like he has a weak case.
roughstuff