In the video he opens the door with his left hand and his right hand is out of view. The next time you see his right hand there’s a pistol in it.
Logically, he either had his right hand on the pistol or the pistol was drawn and in his right hand by his side.
In looking at the video several times, I never saw a gun at all. I saw the action get completely fuzzy and out of focus. Of course, I understand there was a gun - I just never saw it. Perhaps there’s a video I’m missing.