Helmet Fire - With over 1000 hours on type I think I might qualify as a Gazelle pilot which is why I mentioned its handling qualities with the hydraulics off. The amount of pitch nose up on the video must be the result of an aft cyclic input – and that amount of nose up would make a Gazelle climb quite quickly. The lever must therefore have been lowered to compensate as the Gaz clearly pitches nose up and descends.
The highest aerodynamic backloads occur on the retreating side of the disc (starboard side on Gazelle) aft of the abeam point (which is why a helo pitches up and rolls when RBS is encountered). If the hydraulics are deselected the cyclic moves back and right, the lever tends towards mid position (8 degrees) which is downwards for most cruise configurations and the pedals become extremely heavy with a lot of force required to apply the appropriate amount of right pedal. In the hover the aircraft is quite a handful and overcontrolling is easy to achieve (you still have a very responsive helicopter but the amount of force required to operate the controls means that precise movement is extremely difficult).
If the hyds were switched off inadvertently then the sort of manoeuvres seen on the video are exactly what one might expect – pitch nose up and descent followed by a very wobbly hover with a strong tendency to yaw left and descend. The less experience on type the more likely the pilot is to embarrass himself especially if he hasn’t practised hyd out landings for a while.