As you know, the raven does not give you sigils if it casts its spell and runs away. However, it also doesn’t give you sigils if it runs away because of the Terror affliction. I suspect it is the same with rewards for gnomes and battlecrashers. I don’t have screenshot or video, and it’s not something I want to reproduce at my expense, but the developers should be able to pretty easily.
@Jeto I ran out of event sigils trying. If the raven is the last troop remaining and it runs away due to terror, you will get the event sigils. I believe the raven needs to run away before it is the last troop, which was pretty hard to control for after using only event medals for elite levels lol