From my brief examination of the damage, it appeared as though one of Peter's diamond wires snapped clean through about midway between the spreader and the anchor point.

I don't know whether there was any pre-existing damage to the cable or what guage it was. This caused the mast to collapse at the spreader.
Rob heard a loud bang come from the mast area after which he couldn't set the sail properly on one tack. On inspection one of the cables of his diamond set up had slipped through the swage and broken a couple of strands of the cable. Rob has both diamonds on the one anchor point at the base of the mast and the strands had broken about 50 mm from the base on one side. Having seen what happened to Peter, he decided that it would be safer and cheaper to return to shore. Again I do not know whether there were any pre-existing problems with the cable or what gauge cable was used. Rob fixed the diamond wires and was back racing (and winning) next race.