Well, IIRC you have to finish the race to get classified.
However, as the winning car was still some 30 seconds away the race was not officially over. It’s being speculated that the Porsche driver was concerned he would run out of fuel and so pulled to the side of the track. It had been in a battle for third place, but as the car was unable to officially cross the line under its own steam it registers as a DNF.
Unfortunately the news is just as bad for the Clio. It was leading its class at the time and only needed to complete one more lap to make that position official. Instead both cars effectively raced for the 24 hours but leave with nothing more than an expensive repair bill.
K, probably the last post from me, here’s the last half an hour (sport 1 video with radio le mans audio) including the retirement of #65, the porsche – merc battle and the chaos that was the last minute