“That was not the topic here and was not mentioned here, so it did not belong here”
I suppose you are right.
“In any case, if someone tells you that you are speaking LH, the response should not be to ignore it. The response should either be to say, “you are right, thank you for pointing it out.” Or to say, “thank you for pointing it out, but I don’t think it is LH because of ____.”.
What if someone think it’s not LH but have no wish to get into an argument about that? In that case the best thing would be to say “thank you for caring. I don’t think it’s LH and I would like to carry on my conversation now” (I can see how “ignore” might not express this) If that was the approach taken by some posters here it would have saved a lot of fights and harsh words.