I have a couple observations about this clip. First, the "alpha" officer that is driving and talking, approaches the initial situation with his bravado and regular attitude toward the pimps, prostitutes and lowlifes that he is used to encountering on that beat. He treats them that way as he pulls them aside, runs their names and works them for their stories. Not the nicest talk, but probably pretty routine for all involved and a tactic that is probably more effective for him than to go out and be really nice and believe the lies that he gets told 90% of the time.
Things change, I believe, when he sees his silent partner enter the backseat to search and realizes they still have an individual in the driver seat. He walks over and starts to question the driver, as soon as it seems that he becomes aware that his partner is in the back seat. If one thing is certain, the "alpha" officer is not brand new and is VERY security cautious with a good survival mentality. In my opinion that is what ends up working against him since he is already cranked up and has assumed that the type of people he is dealing with aren't the type to be able to carry a weapon legally. Once he is informed of the weapon, he can't see past everything that has built up and it all rushes him as well as neutralizing what has been presented as a threat. His tirade that follows is a mixture of anger, bravado, fear, realization of "what could have happened" to himself or his partner and then eventually that his conduct hasn't been on par with dealing with a citizen that can pass a background check and receive a concealed permit.
I'm not excusing anything he did, just trying to break down and understand a fairly complex situation that was made partly so, by his approach and "hardass" attitude. For a good officer that has taken the "alpha" approach as a survival tactic, this situation would probably be a valuable lesson of the balance that should be involved in dealing with the public, but for an "alpha badass" that just happens to have a badge, they'll never get it and hopefully it's the means to the end of their authority.