Whether or not your assumption is true, your comment added no information. If people are capable of detecting obvious errors, then they would already have done so; if not, then you haven't helped.

Not only does this style of comment prevent others from learning from you, it also prevents others from actually engaging with your point, so that you might learn from them. Assuming that you have nothing to learn from others is, in general, a poor strategy.

(All of that assumes that you're not just bluffing and trying to hide the fact that you have no idea what you're talking about.)