It's hard to say for sure. There's a lot about LV that doesn't make sense, whatever you believe. I think the most likely explanation is that they heard the meteorite and went outside, got spooked looking at shadows and called the police.
The things I find very suspect are the parts that seem almost too on-the-nose. Like the youtube account the kid made to post his video "Alien Society51", complete with the silly logo. Or the camera that was installed afterward on the light pole which the police deny involvement with. And now the family drops off the face of the earth. It's like an episode of X-Files. And the best way to discredit something is to make it feel scripted.
I can see why you think so, but I can't believe that. If that's the case, then that means they saw a meteor at 1 AM and decided in that moment they could capitalize on it? Nah, that just doesn't make sense. I can believe that they might have decided that afterward, when they started getting press attention, but I think the 911 call at least is "genuine", meaning that they were scared and believed what they were saying even if it wasn't actually true.