Just to continue my thought above: That is said in regards to tour and cycling 'tradition' -- which I will be the first to admit I am completely oblivious about. I ride a stationary bike and that is about it for this old fart.
it took me a long time to understand the whole team, domestique, etc etc concepts. I also now understand the 'gentleman's agreement' part like when Ullrich and company stopped to allow Lance to catch up in the past... but I also have to say my personal feeling, from someone extremely competitive is : Fall, broken chain, puncture -- that's blood in the water baby!!! Time to attack and put the threat away!
So, I understand where Sean and others are coming from, and I understand the Tour/Cycling thing is to allow your competitor to catch back up; but my gut instinct would be "he's down? Good! Let's put some major hurt into him now!"
I agree to an extent. However, as you said there are unspoken rules to the sport. And it seems very important that the best man win due to ability and not the bad luck of his competition. A seemingly similar “written” rule would be not blocking the competition in a bunch sprint to the line.