I've already gotten to the heli on Dark Carnival expert before a couple or so times. Once I died in the heli and the other I wanted to beat it with my friend at the same time so I killed myself.
Now, redoing the campaign after a couple days, we keep having trouble with the stretch at the end of part 4. It could be that we didn't manage to procure a bile and save it, or it could be bad circumstances.
So, WITHOUT bile, anyone have tips for surviving this part? On the other times I've played this, usually 1-2 people make it to the saferoom, which I'd be happy with recreating.