If 411A was a true professional, he would realise that not all companies follow HIS take on SOPs. Many, many airlines require a mandatory MAYDAY due to an engine failure on departure. Why a Mayday?
1. As pointed out, many countries do not recognise PAN.
2. It gets their attention (or at least should) and sets their emergency plan into action.
3. Without further dialogue they know you have a problem and will (should) not bombard you with further requests for info, which they invariably do if you don't declare a problem fully and try to play it down.....
4. No reason why you can't downgrade after everything is sorted and you are ready for the approach.
So, to sum up, the PROFESSIONAL pilots will use the most efficient course of action available to them, under the prevailing circumstances to ENSURE priority handling by ATC when it is required. Losing an engine on take off, even on a twin jet transport is, IMHO just such a circumstance as I may be deviating from a SID (climbing straight ahead) or carrying out an Emergency Turn, which ATC don't know about, with restricted climb performance and also carrying out recall drills. Also factor in CRM issues (like very inexperienced right seat occupants) which many EU airlines employ and the PROFESSIONAL captain would be doing a good job IMHO when he called MAYDAY.
Wound like cheap watches? Sounds like a RUSTY OLD TIMER too set in his ways to consider anything other than his own opinion could be correct.
PP