The response in the screenshot reads as a joke to me, the meaning of which is that a fraction of half the Dems not giving an ovation because they weren't there doesn't matter nor actually contradict the point made. If we are being very specific, the claim was just that the Democrats gave a standing ovation, and that is technically true. A ton of them were present and they did that. This is a valid way to express that fact.
I would say that the issue may be that the response could be interpreted as snarky. It's sometimes hard to tell what is a normal joke and what is dunking snark and what is a sarcastic but comradely ribbing. I think it's a good practice for those making jokes to be as obvious as possible but also for those who find them troubling to also directly ask. If it were me, I would have interpreted it as the last one: a comradely ribbing calling out some liberalism.
I do also think that the culture here is and always has been to make fun of liberalism, and with all respect, your counterpoint in the screenshot is liberalism. So for everyone to remain and be comfortable, either the site culture needs to change or we need to make peace with seeing our own liberalism called out sometimes, and even made fun of a bit.
Finally, I think making a joke reference like this is often perceived as the less critical way to engage with someone. Someone writing a paragraph on how this is a liberal attitude might be conveying that this is a much more serious correction than it really is, whereas goofing around may communicate that it is minor. I know this is the opposite of how someone that is on the spectrum may perceive that way of communicating. I'm not sure what the best way forward is but I hope this contextualization is helpful either way.