They can take GPS data from the moment when the stage was redflagged. GPS tracks are recorded and timekeeping is GPS based, so, they can find the time difference between stage winner and Ogier/Latvala from the moment when red falg was applied. It is a bit hard to estimate further timeloss during the same stage as the puncture gets worse. Ogier should win from this decision abit, but it is the clearest fact-based decision they can take.