It’s possible this was just added by the guy for his proof of concept, so I guess we’ll see when more information is released.

So what’s the scenario they are protecting themselves against?

I mean, if you had a USB backdoor why wouldn’t you automate the removal of evidence? It would make disposal a lot faster. You can just unplug it and physically destroy it to be safe.

I think it’s more likely they would cover it on their side with some easily erasable USB drive.

Why not both? Redundancy never hurt.