Prius "rear view mirror" clobbered but the door needs to be replaced.

I just returned from getting an estimate for replacing the rear view mirror on the passenger side of our Prius. The impact seems to have struck right on the door area where the beam is. The body shop guy says that there are ways to tell if they have to replace the door or not.

1. How much give is there when you push on the door right ove the bar area. If there's significant give, that tells you that the beam/bar was affected.
2. You open the door and look at the outside, inner edge of the door jam and there's this squarish area that is obviously torqued.

He says the insurance companies rule this a door that must be replaced.

My own bias is to replace the door, because I value safety, and the guy said that the next time the door is hit, as in a t-bone accident, it is not clear whether the airbags will properly deploy, or over-deploy or not deploy and immediately shrink back correctly, etc. I don't want the car to be unsafe.

I did not do this damage, my husband did, and I don't know exactly what happened. It sounds like he pulled into some parking space and was later backing out and didn't straighten his tires before backing and just impacted immediately at the door and also took the mirror off.

So I want opinions. Does the idea that we have to replace the door make sense to you all. There's some significant, though shallow denting, at least a foot wide, and at least a foot or more tall. The guy said that if it didn't fail these two tests, listed above, it would be much cheaper to fix. They would apply a new skin.