There is a really odd thing that can happen when you lose sight of a caravan during an escort mission.
After some more testing, it seems like the game does the following:
1. When the player loses sight of the caravan, he gets a message to find them again or else they will be in danger
2. About a day after this there seems to be a garanteed encounter in which the caravan gets attacked, the player is again notified of this
Now either one of two things happens:
- the caravan is wiped out and the player loses relations with the caravan owner
- the caravan is not wiped out and wanders around endlessly, but doesn't get attacked anymore. This must be unintentional as a first attack is always garanteed to happen about a day after the initial warning. But if the caravan survives, the player is never notified again and in months of waiting they never get wiped. If they do get in a fight, the player isn't notified of this unlike the first time (which I doubt, it seems like the quest scripting assumes the caravan dies without the players assistance, if this doesn't happen the Quest runs infinitely until the player can find the caravan again)
I let the game run in the background for a while and they just don't seem to ever die, despite dying very, very often in the first attack, on the first day of the quest. This a really annoying and odd outcome for the quest, since it completely locks you out of accepting other caravan quests until you find this specific caravan again and escort it, which can be practically impossible on the world map. I am very sure this is a bug and if it isn't, its bad quest design.