Yeah it's nice to see the police didn't roll up and blast away at the guy holding the gun without knowing what's going on. I wonder if we could get a copy of the audio tapes of the 911 call. Did the gun owner tell the police what he was wearing and explain that he was armed. Did he call or did someone else? This could have been reported as a man with a gun, or even worse as a black man pointing a gun at someone.
I think (hope) most police would react as these officers did.
I understand all the comments about whether or not the driver should have held the carjacker or not. Technically the carjacker could attempt to have the driver charged with unlawful detention/attempted kidnapping in some states. Still I think if I were in the same situation I would still do the same thing, at least up to point of getting the carjacker out of my car and away from me. If he decides to walk or run away I guess I would have to let him, but how many criminals are going to have the guts to test whether you let them, when you have a gun pointed at them.