The overwhelming precedent is right there. Either you use it or you fall behind. 99% of cases you get punished for following the rule, hence nobody does it.
If you want to start applying the rule, this is the worst way to do so. It's less than a month ago the UCI explicitly allowed this to affect the Vuelta. It's likely we'll see more of this today and tomorrow and that those riders won't be disqualified.
I think it's worse to inconsistently apply a rule than to not apply it in cases like these.
Nail on head! If you have rules, then you apply them ALL the time! Everybody wants consistency; then we all know were we stand - and transgressions are applied with a penalty. Cycling is probably the worst sport in applying, or choosing not to apply penalties.
It really is time all the stakeholders came together to sort & re-write rules, and end the grey area of 'unwritten rules'.
I also find it pretty poor that none of the race officials knew until after the finish; surely they have TV coverage in the cars - and have officials back at HQ to communicate with each other. All in all, it's amateur from the UCI....