So I have to support my claims while others do not?
Yes, they should back up their claims as well. But I also don't care about any of the other (yours or theirs) claims, I am interested in that one claim and that one claim only.
They have a higher life expectancy because they have a lower infant mortality rate. They have a lower infant mortality rate because they record infant deaths differently. In the US, if a fetus is delivered naturally, and was not known to already be dead before labor began, it's counted as an infant death instead of a late term miscarriage. Thus skewing the life expectancy stats compared to nations that don't include infants that die during or shortly following birth. I'm not sure how Canada does it, but it's still apples to oranges.
So, again, how does Canada count its infant mortality different than the US? You yourself said you weren't sure how they did it, so how can it be apples and oranges when you don't know there are even oranges involved?