I agree. Cover is cover and avoidance is avoidance, but safe should be a combination of both. Furthermore, in addition to avoidance of known enemy, it should also try to avoid potential ambush. I'd say if you want to be "safe" you wouldn't want to walk on the main road to start with...I don't see how setting Avoidance will help Dave?
I thought the Safest route was an Avoidance route first and foremost, where they will look for the best cover on that Avoidance route if its available?
I can't see that the AI has any route available to it, in this instance, that is not going to take it through arcs of enemy fire.
Its effectively stuck and will probably remain that way until it gets dark.