Is this normal?

[Phantomix]

I use sport mode a lot. The few times I have tried rotating it at a normal speed while going 45-50 mph, it has really lost balance and "glitched" out (not sure how else to put it)
I know the physics of the rotors and why this might happen, just trying to figure out if it is normal or a problem with mine, because its better to find a problem now then after a crash
Here is a video showing the problem:

 

[Kman]

That's your gimbal being overloaded. If it senses a lot of force it will go limp to save the gimbal motors.

 

[ftttu]

Your gimbal reached its max since it was as such a steep angle. If you review your flight log footage, it should show you the message.