Yes, exactly. Assuming that the error was not in the rendering system, which took the bulk of the CPU time and which was isolated as much as possible, the recording could even be replayed at high speed by omitting the rendering of most frames.

I forgot to mention that we actually found a lot of bugs by seeing a playback diverge from the original recording; this was often due to uninitialized variables or reading from random memory. We could generally see when the divergence happened because we computed a checksum of the state of the world every frame and stored it in the recording as well.