- Ignore the bad advice. Keep doing what you're doing, show milestone success (however defined) and move on.
- Nod noncommittally at the bad advice, run a few experiments to placate the manager, keep doing what you're doing.
- Quiet, subtle resistance. Questions like "are there concerns about neighboring-group participation?"
- Open, direct confrontation. "I don't think that's correct, and here's why..."
UPDATE: Before anyone trots out the old, old joke about Rule 1 and Rule 2, I note I've been there already.