Playing Death on a wing, encounter 1. A hero is knocked out and his token on the map. His hero counter is completely surrounded by wall, monsters and boulders.

What happens? No other hero is in position to heal him and if he does his stand up action his turns ends and OL wins automatically. Can he end his turn without standing up and thus prevent a OL win or would ending his turn with his token surrounded also trigger the victory conditions?

The hero token is not a hero itself, it's just a reminder of where the hero was KO'd. With that in mind, I'd be inclined to say that the OL's victory condition is not met unless the hero stands up. The OL victory condition requires that a hero be in a position where all adjacent spaces are occupied by something. The hero figure is not on the board currently, and he is therefore not adjacent to anything. That's my interpretation, anyway.

We know for a fact that a hero is not required to stand up if he doesn't want to. (I'm not sure if that part was in doubt or not.)

I agree with Steve-O.

A hero token is not a hero.

In this case, the heroes' only plan is to have the knocked out character not stand up while the others try to get to him to revive him and then get back out.

Thank you, that's all what I thought but wanted to make 100% sure.

This thread answered one of my questions too for Encounter 1. My son had Tomble Burrowell and used his heroic feat which I believe allowed him to replace his figure with his token and then appear within four squares of the token. He did this just before I surrounded him, so we wondered if the surrounded token creaed an OL victory. We decided it did not (plus Dad wanted to be nice.) Our rational was that although the token was there, the hero was not (he was sneaking around elsewhere). Sounds like we made the right call.