Indirect vassals cannot elude imprisonment

[grommile]

Because a vassal can only declare war on their immediate liege, and a character with a landed title cannot abandon their fief, an attempt to arrest an indirect vassal can be repeated as many times as necessary with no cooldown.

 

[Lessing]

I noticed that, too.

Another thing that happens is when somebody flees and he has a claim, you can invite him back because you could press his claim, and then imprison him.