We're (really) talking about blowing out body fluids and hitting someone accidentally. It's accidental, but still a "wrong". Getting on someone's wheel uninvited and unannounced, also a "wrong", not accidental and could have consequences. But I say that if someone blew snot on me during a ride, accidental or not, I'd be ticked off and they just might get some "escalated retribution" on the pass. He who lives by the boogie dies by the boogie.