The ToC Start
We don't know when it happened, or exactly what it was, only the result.
Sometime between about 3:00pm and 8:00pm, the "Rock Three", Hamilton, Botero and Sevilla went from being pretty sure they were starting today, to being non-persons leaving town quietly.
UPDATE: we're corrected that The Boys (a) weren't quiet, and (b) haven't snuck out of town. There was a press gathering before the start with all in special "red barbed wire" Rock kit, and Oscar at least has been seen around on Monday.
It is suggested that the UCI delivered some kind of confirmation that the three have "open files" for a doping investigation, thereby justifying AEG's position they should not start. We have no idea what form this confirmation took -- and we don't know that the principles, Michael Ball, Hamilton, Botero and Sevilla were given copies of anything. As far as we, the public know, it may have been an story made up in the afternoon to justify a decision that was about to get called into sharp question. And the story was delivered too late to be challenged. The alphabets ran out the clock on Rock, and then ran a trick play.
What is to keep an "open file" rule from being imposed at all races? Probably nothing. Is there anything in the UCI rulebook allowing discussion of open investigations? Not that we know of.
Are AEG and Amgen desperate to avoid a scandal at the race, and is doping a problem for the sport? You bet.
But does that make it acceptable to deny rightfully licensed riders their livelihoods through last minute shenanigans?
It looks like there is never a bad time to bend rules and circumstances if the riders take the punishment.
This may turn into the next play for race strategy. If you can get DQs merely by having an "open file", then planting a rumor in the right place will open a file and take care of someone you don't like, or a competitor you fear. There may be nothing to prevent the UCI from having "open files" on every elite rider, since performing at the elite level is clearly suspicious by itself.
Rant addresses all this and more with lots of comments from both sides.
Bicycle.NET has another story, with the relevant parts of the contract, and the full contract visible for inspection.