Here’s an interesting theory. I read an article on the “Mirror” regarding the Iranian “Ali” who is supposed to have purchased the two tickets. Both of those guys with stolen passports were booked on to European locations which are pretty major airport hubs to to North American flights.
Other than some silly alleged Chinese group, no one has come forward as a logical perpetrator, should this be a terrorist act. The Mirror articles quotes a Malaysian government official as stating that false passport holders with explosives have been detained several times.
If this Asian region is a place to acquire the stolen passports, may it also be the place to acquire the explosives. I would suppose the shoes need to be sized and fitted. It “could be assumed”, these guys were on the way to a western European hub to fly to North America, but one of them had a early detonation. (Not the first time). It would seem strange that Iran would blow up a plane with Chinese citizens on route to China. They are rather close. Anyway, just a theory...