For those of us (like Mr Dickinson) who are regular flyers to Alderney the weather conditions look lovely. I've made that trip many times in much much worse and in a similar PA28.
I'm guessing that his position was because he realised he wasn't going to make the island and chose to ditch in the shipping lanes near a suitable vessel. He would have had the visibility and probably had thought about that option more than once, as have I on many crossings from the South Coast to Alderney.
The fact that his wife was able to exit the aircraft unharmed with the raft and was picked up very quickly by a merchant vessel speaks volumes for the courage and presence of mind of Mr Dickinson.
RIP.