This is what spurred me to give consideration to the idea initially, but what makes me confident is sifting through simply mountains of reports. To get an idea of the volume and typical content, here's a catalog of vehicle interference cases in Australia from 1958 to 2004. Most could be explained by a patchwork of mistakes and coincidences, some require more elaborate, "insanity or hoax" explanations, and if there are multiple witnesses, insanity falls away too. But there is no pattern that separates witnesses into a "hoax" and a "mistake" group, or even that separates them from the general population.