All it takes is a false accusation.
My wife wasn't able to buy a gun because one of her renters swore out a warrant on her for assault. She claimed my wife slammed the door on her foot injuring her. No proof was presented to the injury. They came and got my wife, handcuffed her, and hauled her to jail. This would disqualify her from ever buying a gun. It took 2 years but we were able to get the assault charges wiped from her record. If another renter ever does the same thing they can come and get my guns if I live in California.
Was your wife convicted?
And, I'm not clear on this: DID she try to buy a gun and was unable to because of that, or is it a case that it WOULD disqualify her? You actually say both in that post.