I'm curious if the bitcoins are even still readable at this point. My understanding is the charges in the memory cells of a usb stick will gradually dissipate over time, and after more than ten years, much of that information may be lost.
You could periodically plug a standard usb drive to refresh the memory, but will that work with these hardware encrypted drives w/o a password?
Unless he agrees to submit to random ETG and drug urine testing, I wouldn't trust anything an alcoholic up for a highly-paid and powerful job says about sobriety.