Did anyone ever really shoot from the hip or is it just cowboy mythology reinforced by Hollywood movies?
Certainly it is not the way to ensure accurate fire, with sidearms or long weapons, and my experience was that it is highly discouraged in almost any situation. However, in the early days of light machine guns, it was a standard method of laying down suppressive fire while on the move, and single shot weapons were presumably used in a similar way, I know of several examples from the First World War at least. Very close country, such as jungle definitely encourages hip shooting, because a long weapon is better able to traverse if not fully extended into the vegetation. The idea of actually hitting a deliberately chosen target from the hip though, is beyond anyone but a Hollywood hero at any sort of range long enough to allow the weapon to be brought up to the sight line.
