I see the Carat comes with cabin heat. These systems
typically send engine exhaust through a heat exchanger
that heats the cabin air. A crack or leak in this system
can result in exhaust fumes in the cockpit. I would
expect the cabin heat to be in use on this wave flight.
This scenario would square with the apparent total
loss of control while still under full power. Food
for thought.

This is a beautiful sport, but not without its dangers.
My condolences to Alan Pratt's family and friends.
JJ Sinclair