It does appears that if you / your teammates shoot someone while rogue before manhunt, It resets your timer to maximum of your current rogue level.
I don't know if this is a bug or intended. However it can frustrate people if they have stupid teammates decided to shoot a white name right before the timer expires.
Haven't noticed it. I've seen some odd behavior from the Rogue setup lately but not that one. One man on a four man squad goes Rogue while the others are in an entrance point and the rest of the team does not go Rogue. They can then run with the squad member and protect them as shields. Ran into that last week. Before somebody says it, the other squad members were never killed during Rogue in order to their status off.