To which you respond with "That's an interesting thought."
Don't bother to question anything or correct the mistakes, just impart trading advice that validates the paranoia. Apparently there are "other people here saying things" about this company other than him (who?) and you're the one he's replying to. Maybe you should have asked him, but if you're not going to question it, then while he's coddling you for your research maybe I should ask you (and I did).