I think the defensive move is effective. Admittedly, I have not practiced that type of gun to the neck, defence, but have practiced gun defences. The gloves are a good idea for being on the streets, when there is a reasonable danger of potential assault, in particular from bladed weapons. I may invest in a pair of legal, tactical gloves at some point.
In agreement with the video, I would move my head off the line of attack. My left hand defence would be the same or similar as this officer (it looks like he is a police officer). I would probably simultaneously use my right hand (or reverse, if required) to also grab the shooting hand, or gun if needed, while elbowing the attacker with my right elbow. Hopefully in the neck, or at least the jaw. If I do not grab the gun away from the attacker, I would aim to knock it down and kick it far enough away. While the attacker is stunned, I might use a guillotine choke, if the attacker is facing me from his/her front, or rear naked choke, if the attacker has his/her back to me. But this is only after striking the attacker multiple times with elbow strikes, knees, punches and low, non-grabbable, kicks, as needed.
Striking the eyes is certainly a good option, as are open hand neck strikes.
