It wasn't an emergency... It was a pan-pan, which indicates an urgency level.
A Pan-Pan call should be used for urgent situations that are not immediately life threatening, but require assistance from someone on the ground.
Which seems like it was the case. They also retracted the pan-pan during the fuel dump and after deciding to divert to Vancouver, quite possibly after having established that nobody was seriously ill. Maybe it was the fish, but fishy... Not sure.
Not overly impressed by the communication on either side, but what do I know...