You're giving the guy a lot of grace. Admitting that there could be other reasons why tall guys can be partnered with short girls, especially when given objective evidence supporting these other reasons, is not impeded by a language barrier, not at the fluency level at which they're otherwise communicating.

Nowhere in this thread do they admit it could be for reasons other than their personal theory.

That's just having a poorly justified opinion and doubling down on it when confronted with evidence to the contrary, which deserves to be called out.