Earlier quoted context omitted.
so .. tamper-evident but not tamper-proof?
Correct. I think the main reason is that this "security" is geared more around Customs & Border enforcement than anything else.
With tamper-evident containers, you have a trusted person watch the container being loaded and locked, and then a trusted person watch as its unloaded at its final destination, and you don't have to care what happens at every point in between.