It's really a shame, because that's ultimately a richer and (IMO) better story. But movies need a single protagonist, and switching energy ( from the CIA protagonist to (a) Canadian one(s) ) in the middle of a film like that is risky. The point that America was more constrained than Canada would, I think, have been very entertaining.
Ken Taylor is portrayed as having a great deal of ... courage. You KNEW it was a team effort and that it went all the way up to the Prime Minister, and that Ken Taylor was a proxy for all of the Canadian effort.
Filmmakers who trust the audience are usually rewarded but the process of development leads to teams of risk-averse people who are incented to exaggerate risk. Big movies have the economics of extractive technologies ( mining - you want the big gusher, not a series of modest ones - that in itself is covered by Scorcese's "Personal Journey") and you'd think that would be changing but...
They did make a point of an apology reel during the closing credits - they at least showed Taylor getting the Order of Canada award.