Mutt,
Quote, "I thought that the elevator stayed in the same slightly down position if the lock was engaged or not engaged, the lock just stopped it moving with the wind."
On the legacy Gulfstream models, G550 and earlier, the control column will fall full forward (nose down) when the control lock is released and the controls are not air loaded.
(On the G650, which is FBW, the control column stays in the upright, neutral position at all times unless it is moved. As a side note, there is no control lock on the G650.)