In last game oponent Moran made cautious movement and his koalas moved as well. 2 of my models saw koalas moving but non of them seen beginning and end of Morans movement. Can I shoot Moran on the way since I would be able to spot him there?
So you're saying the Moran himself started and finished outside of LOF but the koalas didn't? My understanding is you could react against the koalas but not the Moran although I haven't actually checked.
You'd only be able to react to the models that 'failed' to Cautious Move by failing to reach a point outside LoF.
Yes, it's specifically listed in the Perimeter Skill. Active Turn. Perimeter Items are activated by each Order declared by their bearer. Each time the bearer declares Cautious Movement, Climb, Move, or Jump, his Perimeter Items will perform the same Skill. If the bearer declares any other Skill different from the previously mentioned ones, the Perimeter Items will do nothing, considering it an Idle.