This is the reply from Bell Product Support Engineering:
Bell Helicopter does not publish what not to do in the manuals, we do not publish any scenarios of things or procedures that are not authorized or approved. We only publish approved procedures.
Failing of carrying the approved procedures (sic) may lead to damage of the helicopter. To answer your question on shut down the cyclic has to stay in the center and collective down, if you pull on the collective it will change the pitch of the blades, create excessive flapping which will result in mast bumping.