Huge red flag here.
LEO could not see the firearm side of the inividual on the bike. When asked he should have disclosed for his own safety before turning towards the LEO to unsaddle from the bike. That LEO could have easily perceived the rider coming off the bike in an armed fashion as a potential threat. (his perception, not the rider's) That is the wrong way to go about a LEO contact.
Was the LEO overzealous? Yes.
The rider even told the LEO: If you cannot look at me and tell my intent with is with a firearm...
If he's truly been to Iraq then he should already know that a person can turn and shoot without giving the cues that they are about to shoot.
Should have immediately asked for a supervisor then shut his mouth.