Getting Subordinates to do more than expected

Last week I was asked how on how I'd manage a situation where the manager has assigned an R&D duty to a staff that has never done that before.

First off, I inquired as to whether she accepted the task or not; and the answer was yes. Well, that means you have there is a person with good attitude who willingly accepts "challenges". However, I was enlightened to the fact that she does not even know where to start & the manager didn't bother to check on her leaving her to gripe to this friend of mine.

Which brings me to the conclusion that :-

1. She's an excellent Dark Management candidate for accepting "challenges" beyond her abilities.
   
2. The manager is fucked

Primarily "because" she has such "good" attitude, the subordinate will probably not tell the manager that the task can't be done until probably the final 2 hours. And secondly; the manager assumes that by divesting responsibility the problem lies with the staff.

As a dark manager I'd apply Principle 5 from "Your First Day as a Dark manager" where you load up your most capable staff to avoid the situation in the first place. Unfortunately; this manager is now forced to apply the methods in what to do when the shit hits the fan.