Originally Posted by
canadiancow
I've flown MUC-YYZ-SFO a few times.
Sometimes, after being at the gate, I decide to exit and have dinner with someone (in at least one case, it was a VDB that pushed my departure out by 4 hours).
They have no idea whether I've cleared Canadian immigration. In that case, I hadn't.
Another time was YYZ-YUL-SFO when YUL-SFO was cancelled. I was definitely legally in Canada, but I still had to go through, because I'd mingled with others who may not have cleared Canadian immigration.
Sorry, can you elaborate a bit... for MUCYYZSFO, you did VDB after preclearing for your YYZSFO flight and then decided to have dinner groundside in Toronto? And if so, you didn't have to clear Canadian immigration, but then had to go through US preclearance a second time once you returned to YYZ post-dinner?