It looks like the inlet cowl departed the engine. Also, you can see a panel on top of the canoe is unlatched and you can see 2 cowling latches (?) unlatched at about 11 and 1 o'clock in the blue area just forward of the canoe. You can also see the oil servicing panel unlatched and open on the right side of the cowl. It could be these panels open mechanically when an over pressure condition exists? But the cowling latches on top, I'm not so sure. A bit of speculation here.
I'm glad there were no injuries, but I think when NTSB gets done it will be an interesting report