I don't think it's too much to expect people to remember the order of the planets.
I mean, if I wanted to bring real physics in, it'd be more that the meteor shower would be obviously 'fake' because intense showers like that are usually A. predictable and B. aligned with Earth's direction of orbit (aka, roughly overhead at dawn). A sudden, intense shower from the zenith in the middle of the night would be cause for concern.
Or that for the rubble to reach Earth from Venus in such a short amount of time, it'd have to be moving at a huge fraction of the speed of light, and thus even small chunks would be slamming into the planet with enough force to choke the skies with dust and result in a mass extinction.
Or the fact that even if it's not moving that fast, that is a huge amount of rubble. Sure, the smallest, lightest parts will arrive first, but then...
Whoopsie-doodles.