This is the usually considered the worst movie ever made. I don't quite agree with that, but it's very close. Anyway, it has dozens of mistakes in it. My personal favorite comes from the main character as he describes the space ship he saw. He claims it was cigar-shaped and in the next line he says it was shaped like a saucer.
He should have said the space ships looked like paper plates since that's what they were made from. They stapled 2 paper plates together and spray painted them silver! The mistake in the quote could also be due to the script being rewritten many times and the fact that the space ships hadn't been filmed yet so they didn't know how to describe them.
They didn't use paper plates, they used real models of flying saucers, or something like that. They weren't paper plates though. It says so in the documentary in the DVD version.
--KMeTG