Industrial espionage is far far more often done by hard work then being clever. Checking the SD cards you use and buying matching ones before executing a swap isn't noteworthy.

If you look through my case of SD cards I have all sorts of sizes and makes/models. I also have a procedure for dumping and formatting, and someone who is handling this most likely would as well. The moment the storage on screen looks funny or I see the card I don’t recognize, I’ll notice.

I’m not saying it’s impossible or I’m somehow immune to being tricked, but you would be surprised how easy it is to leave evidence of tampering through the simple act of trying to take an SD card, whether you swap it out or not. And people like me who handle them regularly would likely notice it in a split second. Maybe we won’t even catch the perpetrator, but it would not be written off as “oh interesting I guess it didn’t record,” if for no other reason then I would go straight into CYA mode and start looking for any hint that I didn’t make a mistake.

At that point if you have a basic security SoP in place and adhere to it you can start auditing.

Anywho again nothing is airtight and a determined individual could of course get past me. But you would be surprised how many hurdles they have to get over, and it certainly wouldn’t go unnoticed and be brushed off as a read/write quirk, that’s really all I’m saying