No but I am trained in information verification.
One source with a history of lying is not reliable and they're also the only source of the confession. Which just obviously isn't how you confirm things.
You also have to account for biases, them being TERFs is actually relevant because Neil is an outspoken supporter of trans rights. That does make him a target of ire for them.
If these do turn out to be true then he's a creep and should be condemned as such.