I still don't think anyone just pushes past their physical abilities. If you take two riders at FTPs of 260 and 270....if both are riding at 280 watts, they might both look like they are suffering the same, but clearly the second rider is suffering just a bit less. You just can't push past what your body is capable of, though I can see someone at a pace they think is going to make them blow up and not realizing they could really be going 5% faster. But thats kind of a small difference compared to the physical difference, and largely one of training and figuring out what that limit is.