As soon as I woke up, I called to find out what happened. The lab tried several more times but after another hour passed, I called again. We knew the guy whose English was the best and I gave him my email address. He sent both Jay's and my copies. Jay's was in Spanish, not that it would pose a problem at the Canadian border. However, our Airbnb host has stepped up to the plate and will be bringing us the certified, signed, and stamped copies in two sealed envelopes! That's above and beyond! Thanks, Alma!
So, we hope to be heading towards home tomorrow. We will still have a bit of a battle getting on our flights without the last sector. Last month, American Airlines ceased operations into YVR on a flight that could connect. Due to the lack of business, they could no longer offer the Horizon flight to get us home.
Consequently, we've booked a hotel in Seattle for tomorrow night and a bus trip to the border at Blaine for Friday.
However, we couldn't check-in for tomorrow's two flights online as the computer is confused. We must 'speak to the agent' at Mazatlan's airport when we get there a few hours early for our 12:35 pm flight. The IATA rules were designed to ensure passenger rights in air travel. However, we couldn't change our tickets to Bellingham, the nearest little US airport near the border, because our destination was originally Canada. This time the rules didn't work to our benefit at all.
I expect a bit of trouble tomorrow but it'd be nice if I was proven wrong. It hardly ever happens that I'm wrong about anything, but in this case, it'd be welcomed.
[Editor's Note: Ultimately all this was for nothing as when we got to the border we learned that only COVID-19 tests taken in the United States are accepted at points of land entry. We stayed in Blaine for three nights and got tests at the Bellingham Internation Airport.]