Honestly wondering if this was done deliberately by DOJ tech folks who weren’t on board with the cover-up.

I have heard of a gov employee keeping a usb cable in a locked cabinet because they thought it had leftover data after use.

(I’m guessing they misinterpreted a zero effort PowerPoint presentation)

Not actually an insane practice. There are compromised cables that look normal but have hidden storage to record data for later retrieval.

That’s the opposite. Your protecting the cable from being manipulated. OP is talking about protecting the cable from being read.