In a way, yes.
When giving information and attempting to pass it along as fact, there is usually an assumption that the person passing along the info has done the appropriate research to back up their "facts."
Granted assumptions often lead to mistakes, stating that "there are no DX10 games out right now" as if it were fact, being proven wrong by someone falsifying your information by simply pointing out a DX10 game, and stating that you "weren't looking" (hence not doing your research) is, whether you like it or not, a blow to your credibility.
If you're not sure of something, just add in "I don't think," "I think," or "in my opinion." In this case, the following would have slid:
"I don't think there are any DX10 games out right now."
"There aren't any DX10 games out that I deem worth playing."
"I don't play any FPSes because I did the real thing (look at my avatar for why), but from what I know so far, there aren't any DX10 games out now."
Granted these are all still falsifiable, you'll look less like a fool saying these than what you had first stated.