Did anyone actually RTFA? This isn't a clear cut case:

Couple get in argument, husband places empty gun on table and asks wife to shoot him...argument continues, wife leaves for night. Next day wife & police arrive, husband agrees to go to doctor. Police promise him not to confiscate guns, then police lie to wife and she lets them take guns.

It's not going to come down to what you think it is. It'll come down to whether or not police can lie to someone...which I'm pretty sure they can (sting operations for example). or it's going to come down to, can they confiscate someone's property with their permission, and whether or not community property applies (husband & wife) and if the wife can legally consent to confiscation of her husbands gun(s).