In reply to Toreador:
> (In reply to Ben Sharp)
> [...]
>
> or in other words, you require the ability to navigate well enough to locate the safe descent.
You always need to be able to navigate well enough to locate a safe descent, the point is that some descents are easier to find than others. I assumed that the OP was capable of rudimentary navigation and just wanted a route that didn't throw up any complexities in descent.
From the summit of Ben Starav you can walk down to the col and turn left to go down the bog. I.e. walk down the ridge and turn left before it starts going up again. In terms of navigation, it's not a particularly difficult escape route, hence why I suggested it.