I've seen this article pop up in a few aviation forums, and I really find that disappointing. It is a very poorly written article with an incredibly sensationalist headline and no real source. The comments range from attacking the US to trying to re-start the cold war with very few actually using reasoning skills.
The US didn't "refuse" the aircraft from landing in the US or at JFK, in all likelihood the decision was made by pilot in command to continue to YYZ after discussing the situation with the company. IIRC, Aeroflot maintains a station at YYZ, and I assume the paperwork and traffic and inconveniences would be lessened by going there as opposed to the always busy, can never find a slot open JFK. Had the situation been more serious (heart attack, some other more urgent medical issue), I guarantee the plane would have landed at the closest reasonable airport.
The confusion likely stems from a translation error (either from language, or exaggeration by an over-extied passenger).