If you've allowed a BG to get close enough that 'retention' becomes an issue you're tactics didn't work. Ditto if you need to reload or need to move at all(you should be behind cover, not just concealment, from the get go). If you're shot or otherwise damaged(even not seriously) you will lose interest in anything else. 'Weak hand techniques' are the shooting games and movies/TV, not reality.
Mind you, adrenaline does a lot of things. Knew a guy who walked off the Dieppe beach with 8 bullet holes in him. One of which was a compound leg fracture, he didn't know about until the MO on the ship asked him how he got off the beach. But under most situations, when you get damaged, you stop. You do not change hands and keep going.