Good news is that you found this out in training. That's what training is for. To teach one what they need to know. When a gun is pointed at you you tend to focus on the weapon. It's perceived as the threat. We are hard wired
to do this. So it is pretty common to be shot in the gun hand. Much more than people think. I've seen this happen quite a few times with people just training to shoot the bad guy targets that have a picture of a gun. So yes practice shooting in every position you can imagine. Truly you just never know.