Earlier today my brother and i were playing starcraft together on different computers i my house.We were fighting against protoss and zerg and we were terran.We were on teams.The game went on for a hour and 3 minutes.Me and my brother won.THen at the score screen we saved our replay.Then we started watching our replay and it was doing wat we did until 13 minutes.Once we reached 13 minutes all of our men and armies were just sitting there and the enimes kill us? 
We won in the real game but in the replay we lost!How did that happen?
Replays don’t save as a video. They save actions that you did. In other words, if one action goes wrong (such as building a nexus) then all of the actions that required that action to work work improperly. Why all your units would stop I have no idea, but I doubt it’s a serious glitch… just one small thing went wrong. Didja try re-replaying the replay?
I replayed the replay 3 times and my the same happened.
i would try playing another game and replaying that one. if the same thing happens i would consult blizzard tech support.