Can't look at the replay now, but maybe some of the track surface polygons were slightly corrupted when you recorded the replay. That would mean the track was minimally different than when it's loaded properly, causing the replay to go OOS if your car ever touched that part of the track.
This can happen if for example the CPU screws up some calculations (overheated) or the memory gets corrupted (overheating / broken memory / a random ray from the secret nuclear test lab nearby flipped a bit / etc.).
This can happen if for example the CPU screws up some calculations (overheated) or the memory gets corrupted (overheating / broken memory / a random ray from the secret nuclear test lab nearby flipped a bit / etc.).