The 24-lap race on Sunday at Motegi was red-flagged at the beginning of the 14th tour owing to heavy rain.
Seconds before the race was stopped, Zarco aquaplaned coming out of the tunnel section into Turn 12 and slid off his Ducati while running in sixth.
Zarco got his bike back to pitlane inside the mandated five-minute limit, but was not allowed to take the ultimately aborted restart.
According to Article 1.25.1 of the FIM sporting regulations, “within five minutes after the red flag has been displayed, riders who have not entered the pitlane, crossing the designated pitlane entry timing point together with their motorcycle, will not be classified.”
Because Zarco did not technically cross the pitlane entry line and instead pushed his bike back using an adjoining service road next to it, he was unable to take the restart and was therefore not classified in the results.
Source: Autosport