Yes, totally can believe it for a lot of reasons. In fact, I think they could easily pull this off at my store. Here is why...
1. Turn over at my store (and I am sure at a lot of stores) is through the freaking roof. Damn near every week, we have at least one new TM being hired to replace one that just quit/got fired. This means lots of new faces on lots of different shifts in lots of different work areas... it would be incredibly easy to pretend to be a new TM and no one would think anything odd about it because there actually are new TMs all the time.
2. As far as the electronics TM opening it for them, again, totally can believe it. At my store, if someone in red and khaki asks you to open something in electronics for them, you do it. Why? Payroll is so damn low that it is almost always one TM back there swarmed by guests. We are constantly calling for backup. (which often times never comes....) If a TM does show up, we assume they either came to help us or got caught by a guest that they are now helping. So, if they want something opened, you do it because it means they are backing you up with a guest.
3. Going on with point two above, we constantly have vendors coming in. Hell, you don't even have to be in red and khaki to get something opened. Just say "I'm a vendor with <insert company name here>" and display one of the 50 or so different kinds of vendors ID's from whatever company you are with, and you've got something unlocked no questions asked. (We have actually had TMs give vendors trouble about this in the past, the vendor then complains to an ETL, and our ETL's damn near threaten to write people up if they "argue" with a vendor in anyway.... so now anyone who says they are a vendor gets anything they want no questions asked..... next thing these thieves will do is probably dress up like vendors....)
4. Final reason I can believe this.... the company has completely gutted AP. How much do you want to bet there was not even one AP person in the store when this happened? I remember years ago it was considered a major issue if we didn't have at least 3 AP people in the store at all times. Now you are lucky if you even have one.