"Simpler" is how it was formulated at the time... nowadays we'd probably formulate it in terms of going with the possibility that least amount of "luck" in its explanation. Something that requires four events with 99% probability is still more likely than an explanation that requires one at 0.004%, even if it is not "simpler". (Those numbers are just made up, not my guess at the odds in question... in reality, the gulf is probably even larger.)
I don't think the odds on filming a meteorite are so bad that it will absolutely never happen, low probability events do happen in the real world (people have been directly hit by meteorites, after all [1], and that's much lower probability than a meteorite passing through a camera's field of vision, which has a much larger volume per second), but for a given claimed meteorite filmed, the mundane explanations are more likely.
I don't think the odds on filming a meteorite are so bad that it will absolutely never happen, low probability events do happen in the real world (people have been directly hit by meteorites, after all [1], and that's much lower probability than a meteorite passing through a camera's field of vision, which has a much larger volume per second), but for a given claimed meteorite filmed, the mundane explanations are more likely.
[1]: http://en.wikipedia.org/wiki/Sylacauga_%28meteorite%29