(Manual control) At any speed ? Including cruise ...................
I think he means direct human control instead of through the autopilot. Not un-boosted elevator control (If that is even possible in a CRJ).
For those postulating complete loss of the HS scenarios, you can probably discount that accident chain. Yes, the aircraft would pitch nose down initially, but it would continue pitching, much like the Metrojet crash, and the impact would be with much lower energy.
With any high speed departure of a THS equipped aircraft from level flight, Mach-tuck could make it harder to recover and would probably require judicious use of HS trim if it got into that range-but that is all theoretical test pilot stuff. There is also the Hoot Gibson maneuver that can be used to shave off unwanted speed. (Dropping the Gear) Results not guaranteed.