Since we are being a bit pedantic, lets take another look at what Pan and Mayday mean and using that look again at the posting by 5 miles baby.
Pan - a state of urgency
Mayday- a state of distress
5 miles baby replies to a call stating "medical emergency" with "pan acknowledged".
To me that is putting words in the mouth of the pilot and could be seen as guiding him down the road of urgency when actually a state of distress exists.
If the controller takes such an action and subsequently a mayday is called by another aircraft, then where does the controller stand if in fact the first pilot wanted to declare an emergency and should have used mayday because that it what the situation required.
Not at all happy with controllers putting words into pilot's mouths cause they can be the wrong ones.
Far better to either ask the question or if no sensible reply, work on the worst possible case scenario.
Currently, the information provided to crews from the UK authorities state that "fuel emergency" will not obtain any priority unless an emergency is declared. There is no mention of limiting the alerting service provided in any other situation regardless of what words are used.
Thinking of how hard it can be to understand comms with an oxygen mask and howling gale, I would not like to have my attempts at making an emergency landing twarted by my inability to communicate the magic word.
Situations like the one described in the post by Barry Cuda require reporting and action from the CAA because obvously that pilot never heard the story of the pilot who called wolf!
Regards,
DFC