In my case I had the tap on the pole - strapped on using cable ties and the resultant loop in both cases caught on something on the ground yanking the hose out together with the toothy clips. Clips lost, valve useles. In contrast I have had the same gas type tap for three years. I went with the new tap when I bought a CLX but have now reverted back to the old tap.
This would explain it - that must have been quite a yank as usually they will either hold tight or the hose will pop out. I have put a link to the video showing how I use these valves -
http://youtu.be/cS51l4oY2mgSome clients do find that attaching the valve to the pole works well, but I have always found that this seem to get in the way of me holding and using the pole and it does create a permanent loop which as you have found can catch on things.
Perhaps for your usage a bulkier more robust non-push fit valve is more suitable.