I think you can tell he is gay when he talks, but he`s not super lispy... not that lisp = bottom anyway. I have read his blog (written in hilarious broken english) and he talks about being on a photo shoot with straight male models who were covering their cocks around him and he thought it was funny because he only cared about their butts anyway. Still, wouldn't be surprised if he's bottomed before. I think it is pretty rare to be a gay man and to have NEVER bottomed at least once.
PS My friend is very effeminate and a drag queen and he's a top... so there you go. Having a lisp means nothing