I used to fly 747 Classic freighters Hong Kong to Seoul to Anchorage, where we did a running crew swap with the ongoing crew operating the last leg to Chicago, and of course the reverse on the way back.
We were HK based and the others were US based.
I always thought it was quite funny the way the customs/immigration guys carried on there at Anchorage on arrival of the airplane.
The crew van pulled up at the bottom of the steps as the airplane shut down, we had to get out of the van and wait at the far side of the van to where the steps were, then, the arriving US based guys were herded directly into the van, via the opposite side of the vehicle, without any contact at all, no actual speaking to the other crew was allowed!
We all though it was a great joke the way this was done, but as usual, the Yanks were very serious about doing this silly procedure, even though we spoke (loudly) over the top of the van if there was something important to impart about the airplane.
What made it more of a joke was that we were never searched (body or baggage) at any time, nor was the airplane!
EW73