It makes sense that a thief may have dropped the card. It wouldn't be weird for a thief to ditch the card anyway. But they may very well watch it first.
Then realizing what they found, obviously not have the stomach to throw it away. There is a huge difference between a thief and a sadistic killer. A thief wouldn't want him to get away with it either.
I tend to think that the thief himself may have labeled it. I think if the killer labeled it the label would not be so pleasant. I think it would be something that only he would understand. Or something he would remember about his victim.
You know how some serial killers remember certain things? Like one victim took a long time to die, or one fought harder, or one bit him.... I think it would be something like that. I don't think it would be so straightforward and blunt.
Is it possible she is in shock or not ready to process that her husband is a killer. Once reality hits then you have to question every detail of your life with that person. Do you feel guilty for missing things?
Just imagine how stupid you feel when you realize you've been cheated on... and you missed the signs.
Then magnify that by about a million because you didn't realize you married a killer.
Then throw in survivors guilt because they are dead and you are not.
Then throw in the guilt because you might have been able to save them if you had made plans with him that night or something.
I'm thinking if you had a good relationship with your husband you might say NO to it immediately. But things... suspicious things might start coming to your mind. Some might stay in denial....etc.
As far as we know, women are often in the dark about 'goings on'. Some guys are extremely good liars.
Absolutely most would immediately go to a no.
Honestly I hope that investigators are able to isolate some audio from the video for her and play it. Like bridge guy. So she doesn't have any doubts, if she still does.