People normally interpret other people's statements according to the context implied. So for example, if I said, "So how come you haven't given yourself up for committing serial murder?", people would assume that I think you are a serial murderer, and they might even describe this by saying that I said you were, even though I would not have said that in a technical sense.

In the same way, "Caleb doesn't have enough karma," implies the context that he has a Less Wrong account with insufficient karma, and it would be normal to say that you said this, as Lumifer is doing, even if you did not do so in a technical sense. It was in fact quite unnecessary to do this, nor was it necessary to use three sentences. You could have simply said, "Caleb doesn't have a Less Wrong account yet."

That said, since he does not appear to have shown up in the comments yet, I rather suspect that you might be the motivating force here and that really he is not all that interested in posting on Less Wrong.