Yeah the tool was created in 2000, in fact GP3 2000 season (and Gp4 as well ) included by default the long replay.
about the bug,
I am not sure if it is about the .md infos in the track or some bug with cronometer when long replay, anyway when there are changeble weather, in general changeble conditions on track,
if you were player (it not happen when none driver is selected) , the player car follow a different realty in replay.
All commands are replicated , but the physics seems different and at the first turn car will go out.
I didn't find any solution to this problem.