Sorry Dave, maybe I'm confused. I was talking about this type of moose stall.http://generalaviationnews.com/2013/06/30/beware-the-moose-spiral/
The classic low, slow, looking back in a turn.. In Alaska it happens so much while guys are looking at wildlife they named it a ' moose spiral. Or moose stall'
What we call a 'mustering stall' is the same as the 'moose stall' It happens when the aircraft is turning steeply and slowly around a fixed point, (more often in wind), and where the pilot is asked to 'lift your wing' so that the pax or cameraman can see the target. In nil wind - it's easy to fly a constant angle-of-bank turn, and remain in position over the target. In a high wing, this keeps the target 'under' the wing, and provide the aob and balance remain constant - it's as safe as you can make it. However, once a pilot applies 'top' rudder to yaw the aircraft enough to lift the inside wing - then the IAS decreases rapidly, and if the aircraft stalls, it rolls 'up' and out of the turn into a spin. The nose drops alarmingly and recovery requires a lot of clear air!
The opposite of the 'mustering' or 'moose' stall is where the rudder is applied excessively in a turn, causing the aircraft to stall in a 'skidding turn, then spin 'under' or into the turn. This is more likely where the pilot is trying to increase the rate of turn, (usually base-to-final). It can occur during low level ops but is far more likely if the aircraft is being manoeuvred around a point in winds of 15-30 kts and the pilot has not the skill to fly a varying angle-of-bank turn to keep the cameraman with a constant view of the target. If you are very low, the spin can't develop further than the nose dropping rapidly 'into' the turn. This doesn't always happen - it's entirely possible a pilot can just allow the nose to fall into a left hand turn as power is applied - and in a split second the aircraft impacts nose and left wingtip. Aircraft not stalled or spun - just 'uncontrolled descent' into the water.
Low level manoeuvring around a ground target is incredibly dangerous unless the pilot can fly variable a-o-b turns in gusty, windy weather, and never have the stall warning squark once. It requires very good power and balance co-ordination, and is something which needs to be practised often. A 30 min session at 150-200 ft, x 60-70 KIAS doing 30-45 aob turns - in wind - is essential every 2 months or so. LL endorseed pilots still need to practise. The endo is not a skill that serves you longer than 6 months really.