I heard it was only a visual thing for the actual autofinisher, and that the other racers REALLY get a DNF.
No one, not a single person (even though the thread claiming they do is 22 pages long on the official NFSW forums),has proven that the other racers get a 0 second time on their stats.
If someone would care to test this with a bogus account playing clean, go to a MP race and let someone autofinish. Then go check your stats on NFS-S and see if it really even does give you 0 seconds or not.