"Of course there are no first hand accounts, who would admit to that today?" This is a textbook case of the argument from ignorance, which is a kind of Affirming the Consequent. If the Alligator bait stories were true, there would have been no first hand accounts. There are no first hand accounts. Therefore the stories must be true. This argument can be used to prove the existence of pretty much anything.

I discuss this fallacy here, along with it’s evil twin denying the antecedent
https://teedrockwell.medium.com/the-formal-fallacies-d0679297c9bb