The ReplayMod records things (practically) exactly as you would see them while playing with all implications which that entails.
Meaning that in terms of reach, etc. it cannot decide as accurately as the server can but should be (practically) exactly as acurate as any client-side screen recording.
Note that there's an exception to this: Jumping in time. After jumping in time, entity positions may be off for half a second or so. After playing for a few seconds, everything should be in sync again.
