Dude were you in a car or a motorcycle ? I know this might sound stupid, but if I was in a car , I'd let him almost pass me , and hit his back side and keep pushing him till I get him dead, passed out or untill something stops him, or I throw him of the edge of that rode, then Call the cops and tell them the fucker pointed a gun at me.... These stuff make me feriouse ... Glad you are fine dude