You guys promote checking stuff out for yourself, relying on your senses to discern the truth of the world we live in. Yes?
Yes, with a side dish of... oh, wait. You already said it. We're in agreement then, great!
But if you're going to promote that approach then it's a bit hypocritical when someone presents an observation which doesn't confirm with your worldview to then tell them that their observation was wrong.
We have ample evidence, both experimental/observational and theoretical, that the vast majority of people who claim to have made this observation haven't actually made it (and would be physically unable to) - they simply thought they did. The basis here is not whether or not he agrees with us, but rather the likelihood of him being correct, regardless of the Earth's shape.
Ultimately, you believe that many people won't be able to make good observations by themselves (you're correct), but you choose to selectively not apply it to a creepy TV personality for... reasons. I suspect those "reasons" are that he thinks the Earth is round, and therefore you think he's correct. It seems to me that you're guilty of the very fallacy you're accusing us of.
But if people's observations aren't reliable then how do we discern reality? How do we know, say, that in the Bishop experiment he didn't just "see what he wanted to see"? And if I repeat it then what if I'm just seeing what I want to see?
People's observations are reliable when performed rigorously and in large numbers. Each observations is a piece of the puzzle. Some will be incorrect, because humans are silly meatbags who are easily tricked. However, these failures are less common if the observations are kept simple, repeated frequently, and diversified. We look at the preponderance of evidence, the bigger picture.
For example, you think the Earth is round. That's fine. Let's humour you and pretend that it is round. This does not mean that every meatbag observation that concludes the Earth is round is correct, or even plausible. In this case, it very likely isn't. You should be able to notice that without acting like your broader viewpoint is threatened. It isn't.