Just keep on asking questions - "Maybe I've missed something - can you run that by me one more time? No, I'm still not getting it, are you sure you're not leavi

Just keep on asking questions - "Maybe I've missed something - can you run that by me one more time? No, I'm still not getting it, are you sure you're not leaving anything out? Well that doesn't exactly make sense, what about xyz? Whoa, back up, I'm a little slow buddy, you're going way too fast for me. One more time?" You do have to be pretty loud when doing this, because people will get frustrated with you and be like "Nevermind, everyone else gets it, lets go". At that point you really have to insist. But logical flaws will quickly become obvious.