If you look at the top of the article at the link I posted there is a flight/windshear profile from Flightradar24 at the location and time of the flight.
The plane was at about 1000 ft and dropped at exactly the point a strong windshear was occurring.
That could just be a coincidence I suppose. If you have any evidence the pilot had a heart attack or stroke, please share.
Everything is speculation right now.
Per https://flightaware.com/live/flight/N725TH/history/20220904/2150Z/tracklog N725TH here from 462' to 900', probably sightseeing flight, last minute local time at 15:07:56 altitude 900' at 144MPH, 15:08:26 still at 900' 142MPH, 15:08:49 suddenly air speed reduced to 115MPH (?) last altitude reported at 900' and no further transponder data? Deadstick or engine problem the pilot could have easily glided the plane to a emergency water landing, the DHC-3 Otter stall speed is 58MPH? N725TH probably nose dived down in to the water at 115MPH? At 900 feet I would have lots of chance recover it if flying a Cessna 172 plane? I don't know where you saw the local weather in the vicinity of the crash, you're just speculating of windsheard, right?