Planes crashing out of the sky wouldn't have been inconceivable. Say you have two air traffic control systems that are synchronizing - one handles dates with a modulo 100 (00-99, i.e. 1900-1999), another handles them in epoch time. All of a sudden the two reported time + positions of two different planes don't match up by a century, and collision projection software doesn't work right. I've seen nastier bugs than that, in terms of conceptual failure.
At no point is that a theory about a "conspiracy" either, IDK why you're bandying that term around.