“There are no new accidents, just new victims.”
Reports from national marine rescue organizations usually include all types of rescues and not just ones involving surfskis. As such a number of the links collected here may just be starting points that you will have to narrow down further in your search specifically for surfski or downwinding related reports. But some of the collections such as the ones from surfski.info or Whatcom Paddlers are almost exclusively related to surfsks and/or downwinding.
Extreme Miller's Run - Can you see paddler lower right center? photo: Surfski.info safety gear article