Just as in an outbreak of mass hysteria, only a portion of the population is going to be affected.
During a flap of any kind, there are people who are going to be more attuned to the false belief, while the largest part of the population, the more stolid folk, stand around wondering what the heck is going on.
The most attuned people are going to share certain personality traits. There's a small core of "superspreaders" - a majority of the reports will be generated and spread by this small core.
The superspreaders are aided and abetted by local news media who have a different agenda. The want a story to sell. So they "interview" the superspreaders. This interview is an uncritical fluff piece. Everything the superspreader says is uncritically accepted as fact.
Sometimes you get a convergence. A member of the local news media becomes a true believer. Then you get an ultra-spreader. Either way the "silly season" starts. The silly season is something like the "Summer of the Shark."
Later a more professional member of the media will come along and start doing more analytical, common sense stories. They'll be shouted down by the true believers. The more uncritical members of the media will be "skeptical" of the mass delusion explanation, citing that the witnesses are solid citizens who must have seen something "real." It's not "fair" to criticise (read as "insult") solid citizens, some of whom are police officers or pilots!
The more stolid folk - the majority - won't care either way and won't engage in the debate. They'll just turn to the sports section. (Read as "swipe left" in the current vernacular.)
And by the time the analytical stories start coming out, the flap is already dying a natural death.