Capt F You are absolutely right and EXACTLY what I advised the pilot when I was contacted very shortly after the incident, for the same reasons you mention. I also told pesky journalists that spent Thursday evening hassling me that I had given this advice and that I had nothing to say to any of them.
I have said here a few general things about ditching, forced landing training, insurance, Cherokee systems, how the ATSB respond to these things etc as I've probably got more insight than some, but I haven't and won't speculate here or anywhere else what caused it because I wasn't there and I don't know, though as someone who operates Archers I am obviously keen to find out.
Suffice to say I would have handled the aftermath very differently and - I'm done with all this.