A DH8 had an altercation approaching YBRM about 10 years ago. The eagle went through the fibreglass wing-root to fuselage fairing, taking out the wiring to the left (I think) engine, cracking the wing spar caps, and causing the spar to bend rearwards. Many, many months out of service.
If Mr Bombardier says max 250 < 10,000' then that's it.