Hard to believe ,somethings not right .common you fall overboard with no sails up and rudders are up .9 hrs in the water without fatigue or salt water sores/sunburn then end up next to your yacht with all that coastline and some strong tides. Um !!!
It is possible for a cat to do this. If it was motoring, then the sails would be down and if the boat hits the sand going forwards then the rudders are designed to kick up. I hope I could swim 4 miles if I had to, good idea to wear the inflatable all the time when on your own.
I also like the idea of a little bum bag, with a VHF and a PLB/AIS transmitter. I know we are supposed to stay clipped on but if conditions are calm it is less likely, very unlikely. So a bum bag with an inflatable harness is a good compromise. Well done to the owner, biggish tides around there, and sharks and crocs.