On the balance of probability, the standard I believe The Coroner is held to use, the significance of a bird strike, turtle strike, flotsam strike etc would be far outweighed by the obvious medical incapacitation which The Coroner appeared to address.
Had this been a submission to The Coroner, I have no doubt he would have paid it scant regard to it. Depending also on who submitted this theory based on, an assumption of a probability. (what evidence)?
Did any submission seek to put a 'red herring' in place to apportion, move or remove blame on the submitter?
That's not the job of a Coroner by the way.
I do have serious reservations about some of his recommendations.