This could've been rendered relatively secure had the USB stick been potted, but I guess that would've cost an extra few cents. https://en.wikipedia.org/wiki/Potting_(electronics)
It was potted (page 19 of the slides https://github.com/xusheng6/breaking_encrypted_USB_drives_wi... )
> an interim fix using epoxy over the card
It was
Potted shouldn't matter; if the data is encrypted it doesn't matter if the bits are readable by anyone
Too expensive at scale