Because they spotted a contradiction in the original argument that the other person did not consider before making their argument?
Because they spotted a contradiction in the original argument that the other person did not consider before making their argument?
It's like reading an entire article and pointing out a typo without engaging with any of the context. It's easy to find a single fault and point it out loudly, but if you don't even try to engage with the intent of the message, you aren't providing anything of substance.
I would not consider typo to be a contradiction.