I don't think the poster was saying anything bad about you. It made me kind of wonder, too. I mean, if my child told me that our long time family friend abused him, I would definitely act as if I assumed he was telling the truth until I found out for sure otherwise. Plus, a child falsely accusing someone has got something going on that needs to be addressed.
Whether anything needs to be addressed depends entirely on the words the child used, and what the child actually intended to say.
Sometimes the child means to say something innocent, and it comes out all wrong. For example...
I was picking my daughter up after a preschool gymnastics class. As the coach (a young female college student) hands her off to me, my daughter says happily, "We played the Underwear Game today!"
Her coach goes sheet white and says, "We don't do anything with underwear!"
I smile reassuringly at her (since she looks about ready to faint) and ask my daughter, "What's the Underwear Game?"
My daughter starts to ramble on a bit, and it's getting worse as she's saying things like, "And then she puts her hands on my bum...", as the coach is simultaneously saying things like, "We're never alone with any of them, you know..."
But finally I manage to put two and two together and realize my daughter is talking about holding onto a bar and being lifted up into the air by the coach.
"Pull Ups!" I say, "You did pull ups today!"
"Yes," says my daughter happily, "The Underwear Game!"
Because, of course, "Pull Ups" is not just the name of a gymnastics move, it's also a brand of diapers.
My child was definitely not accusing anyone of abuse, but if you didn't know what she was talking about, it might have sounded like she was.