Essentially, you said you have seen plenty of people using profanity on FR and he said not true, but can’t do that because he would have to know exactly what you have seen. He was basically saying that you were lying about what you saw.
A simpler reaction could have been, “That’s odd, I haven’t seen them” instead of going into orbit and accusing you of all kinds of things that simply were not true.
You are an enabler and are dangerous to your sisters, quit trying to cover for her, she admitted her error which caused me to respond in kind, so let it be, you seem to be an instigator here.
Actually his not true post was to my original comment that you can find profanity here. I posted the other comment after he said not true. But basically yes, he implied I was a liar and a troll.