Hacking is a Myth ,it’s really the Thumb Drive
thumb drives are so five minutes ago...it’s 16GB SDHC cards and such (maybe 32 or 64 GB now)...
My first computer in the 80s, cost $7000~ IBM. It had a 10 or 20 MB hard drive (I forget)! Remember 5 1/4 inch floppies? The floppies at work I used were 8 inchers!
It doesn't have to be "either-or". The thumb drive is just the way he stored the data and removed it from the facility. How he accessed the data is another question - did he have that level of access as part of his job duties, or was he able to elevate his permissions to access data he should not have able to access? If so, that would rightly qualify as hacking.