Can vehicle 'horizon lock' be turned off?

When in a vehicle seat, the camera pitch will lock onto the horizon for a few degrees. Is there any way to turn this ‘feature’ off?

This was introduced somewhere in a GMOD 10 update.

If you don’t know what I am talking about, it can be seen in a test I made here. When in the vehicle seat, as the camera view passes the horizon it will lock and cause it to stick in place for a millisecond. If this problem was not here, the camera would be super smooth on this track.

Check out 0:33 and onwards.