For the record, as far as science stuff goes what Wishy is saying is that:
A) If scientific evidence strongly supports one theory, and something goes against that theory, regardless of whether it's positive or negative, then you must disprove that theory for that something.
B) If no scientific evidence supports either position, then you must prove the positive since the neutral position would be the negative.
This is how both science and mathematics works, and how shit is created falls firmly into the realm of science.
He's also saying that religious arguments are silly since it's very hard to convince somebody that their belief is wrong because you have no concrete evidence, and even if you did they'd come up with some absurd reason to not believe the evidence.
Now whether or not he was coming off as a rude troll is up for debate.
He does make a couple of decent points, though.
EDIT: @Purple: You realize that he's from Argentina, right? His Spanish is probably perfect.