Why is the driver unsafely rejoining the track on the racing line?
All hypothetical obviously but I would guess racing drivers being racing drivers they would run wide, join back onto the track onto the racing line in the hope that they got away with it, and then the power would cut out. Either that or they'd have to join the track and instantly pull across it to get off the racing line, which would also be hazardous.
The other option is to stay off track, but that would be unrealistic as they'd 1) be picking up marbles/dirt and 2) they wouldn't really know if their power was being cut until they join back on to the track anyway, as we're dealing with a tenth of a second or so between them going off track and coming back on...
It's a nice idea but I could see it causing issues.