I haven't listened to the audio, just read the transcript. The kid was being an ass, but it's the trooper's job not to lose his cool.
IMO it was a set-up. A sting. Looks to me like it was very carefully planned, to maximize the "piss him off" potential, and, to start the ball rolling by giving an answer indicating that the kid was high -- but doing it in a very Clintonian "plausible deniability" way (high/hi).
So, the cop screwed up, but it was due to some heavy duty "bear-baiting."
This kid ain't no poster boy for the Bill of Rights. (And I'd really like to know who he's sock-puppeting for. ACLU? Soros? Something stinks really fishy about the whole thing.)
Obviously the police set themselves up for it too, if for no other reason than being there. All this "papers, please?" crap is an open invitation to all sorts of abuse, from all directions. It's bad, period. It does NOT belong in a free country.