Factual error: The spider being fried by the fuse box simply can't happen. Fuses are insulated for that very reason.
Factual error: Jerry Manley's corpse wouldn't have been returned to his home town as depicted. He died in a foreign country outside the U.S. from what was thought to have been a fever, his corpse would have been quarantined for possible contamination and autopsied which would have quickly determined his real cause of death from the spider.
Factual error: With Irv and Blaire, one of them picks up the handful of popcorn and presumably eats the spider. While inside the eater, the spider would bite and poison whoever it was inside. When they find both of them dead, the spider crawls out of one person. Why would it leave one body and actually take the trouble to go inside the other rather than just bite them on the skin like the others? It's not like it would crawl out and back into the bowl to be eaten by the other person.