How? If they ask, lie.
Some people are honest & wouldn’t even think of lying. And this means that family or “others” have an easy means of stripping veterans of their 2A rights.
I once told a pediatrician in the practice we used for our child (at the time) that I saw their gun questions (which at some level were being forced on them) as boundary violations. He got a little huffy, I told him they weren’t firearms safety experts, nor pool safety experts, nor household safety experts, they were physicians and should stick to their knitting.
I think that was our last visit there, as the kid was aging out. Probably for the best.
There is a Gulf War vet who buys their firearms from our shop. She has had emotional issues but she never seemed very bad to me. Then suddenly she was denied a purchase by the BCS.Turns out her doctor at the VA decided to flag her. She was furious and after legal wrangling and threatening to sue, she got her rights back.