The weight of the boom at that angle would load the circuit. When a hose breaks it is usually a gush of fluid. A pinhole to the cylinder/fitting makes the spray. I have seen defective cylinders do this exact thing in field tests. It is almost always in the tubing welds on the cylinder.

Edit: also the lock valve is built into the butt of the cylinder. So hose failures would only leak fluid trapped in them. It would have to be cylinder damage to both allow the boom to fall, and have pressure enough to spray.

The weight of the boom at that angle would load the circuit. When a hose breaks it is usually a gush of fluid. A pinhole to the cylinder/fitting makes the spray. I have seen defective cylinders do this exact thing in field tests. It is almost always in the tubing welds on the cylinder.