Typically it's a bit harder than that as not every shipment is millions of dollars in stuff.
My father was a transportation manager for years, and his first rule is when expensive shipments are targeted and inexpensive are not it's an inside job.
Not sure why my original post is downvoted, it is following all publicly available information about this case so far.
This is just one shipment of several that would have been siphoned off over the past year or two.
Oh and another fact, news of the nVidia situation got out to investors and was the source of the recent broad market sell off, even though this was all insider trading based on information that has not been released publicly.