Looks like the batteries might have come adrift and went through the bottom of the boat on the port side. One large hole to fix. There's photos on the net. Going to need a few rolls of duct tape.
In an interview this morning, Hutchinson indicated that the runner wasn't the real problem - those mains are never eased out so there isn't much adjustment travel on the hydraulic mainsheet or traveller. On really fast sailing craft, easing the main can cause major problems. On foilers when you ease the main, the downwards pressure on the foil reduces and it will lift above the water level and crash on re-entry, which is similar to what happened to the Americans.
He also indicated that the hole was caused by water impact rather than an object; both batteries remained in the boat.