VA health care has never been the best. My dad a WW2 Vet died of lung cancer they 'failed' to find until it was to late.
Chest xrays every 3 months and they just missed it? I don't think so. I think they found it and just let it kill him as he was getting to costly to treat because of age and health. Official cause of death is lung cancer, when actually the pain meds stopped his heart. When they did 'find it' they gave him 6 weeks to live. He made 3 months in horrible pain.
He was a career boilermaker at a large steel mill after the war until he was injured OTJ that disabled him and caused him to have emphazima. No rules about safety back then.