Editor:

1. Place a car, player as driver.
2. Place four infantrymen in close proximity, so they are linked with player.

Ingame:

3. Tell them to get in.
4. While driving, order "all stop" (tilde, 1, 6).
5. Stop the car and swith to external camera.

6. Observe the passengers disembarking without an order to do so.

AI drivers and gunners stay in.

I found it out, while having several armed vehicles in group, with "surplus" AI teammates as passengers. The drivers were going haywire with pathfinding, so I quickly ordered all stop, otherwise they would have crashed into forest. To my surprise, AI people started getting off from all of the cars. Now imagine this under fire...