I've seen this several times in projects, not in defence though. I've heard of it there though. In one instance, we were building a bunch of very bright lcd d

I've seen this several times in projects, not in defence though. I've heard of it there though. In one instance, we were building a bunch of very bright lcd displays for big video ads in times Square. This was when it was a cutting edge thing to do. To deliver on our project, we needed to buy every single Golden dragon 2 white led in the world at the time (200k or so). We bought the entire stock of digikey, RS, mouser, etc. all at once. For each led also needed a zener diode, which we had similar issues sourcing. Once all the boards were built zeners started blowing up and literally popping off the boards. It turns out about a third of thr zener we bought, from reputable suppliers, were counterfeit. No way to know until they blow up.