Nick,
What I find amazing here is that Some ppruners seem to say that if the one word is left out, all bets are off on ATC responsibility. If you don't say Mayday, ATC can just ignore you, I guess you believe. I don't agree!
If you include me in that, then I am obviously not making myself clear, and I apologise.
If the word Mayday is not used, I am not saying ATC will ignore you, but they
just might, for any number of reasons, some of them perhaps valid.
Despite all the replies on this thread, several from me, I think your initial post says it all. The pilot used non-standard phraseology, he did not receive the service he desired, and he complained. If he had done his job professionally, I'm sure he would have received the service he had every right to expect.
To paraphrase the title, "When is declaring an 'Emergency' not enough?"
Always.