I have no way of knowing what really happened, but I sure feel for you and think it's great you speak up for what you believe.
The comment... well, if you behaved in any way similarly to hiw you sometimes behave here, there is of course at least the possibility that someone played along. Like here.
If you call people agents, they sometimes say "yes. And we're coming after you."
Not very nice, but typical internet occurrence.
This is not saying you are wrong. I don't know. And I don't know because there are many possibilities.
I've been on the other side of you calling me an agent, claiming I'm threatening you etc, so that obviously biases my perspective.