The mission timer said I failed the mission at 49 minutes left and I can't redo it.

[SpartanCommander]

I was on "catch the council spy, Or not" and I have plenty of time was looking for the spy and nothing got by me and suddenly when the timer reached 49 minutes left I suddenly failed the mission.  Not I got payed by the council and the plot moved on by I would have liked to have actually have done the choice wanted to explore more on that radio missions and I'm reluctant to continue due to I'm not sure how I suddenly failed the mission.

[Rudra]

How many paths did the map have? Depending on the map, the spy can slip by without ever encountering you. (Edit: This can actually happen on multiple missions where the target starts as a runner. Makes knowing in advance the different ways the target can go and watching the chat window for the target's chatter almost a requirement.) (Edit again: Especially if the map has elevators since the target only has to reach an elevator to escape.)

 

Edit yet again: There is another possibility, but I've only ever seen it happen I think with Crimson, so I don't know if it is a bug or if it is something that specifically Crimson can do. What happens in this case is Crimson ignores the map and beelines through walls. Which means you have to navigate the map to somehow get ahead of him and hit him while he is still in a room to try to stop him, only to then race through the map to hopefully head him off again when he goes through the next wall.

Edited March 9 by Rudra