So if this indeed the case, the "roster" is not the legal document, any old tom dick or harry could make up any times they wanted, it would not be "illegal" as its only the roster i.e. it is not the "plan"
When issued with the "Flight Plan" it says "ATC Plan" so therefore that is, by definition "the plan".
What a load of twaddle, the roster IS the plan that crew have to work to, flight times are done using a standard aircraft speed and a company set head/tailwind bias, standard turnround times are then used to produce the roster, it is possible to use high speed cruise figures to reduce these times, but to reduce turnround times you would need to have good justification, and a non normal operation will rarely achieve better than standard turnrounds, this is where TCX got it wrong, they cut down on flight times and turnround without justification to fudge the duty.