I suspect the problem with time travel involves counting. For example, when the argument's opening salvo of 'So I'm going to try to argue the grandfather paradox in the following manner with 2 assertions:' is immediately followed by 3 assertions, it becomes clear that even discussing time travel precludes one from doing the maths that would make a discussion of time travel possible.
Boru
Boru
‘I can’t be having with this.’ - Esmeralda Weatherwax