Patty, if you are a Skipper, I would not like to be a fare paying passenger sitting behind you. If you are a Co-joe, you are a long way from Command.
Ofcourse it is an Emergency and of course it warrants a "mayday". Public Transport aircraft certified for operation by TWO pilots means that if you lose one, you are in a non normal. This non normal will be addressed by your company sop's. I suggest, drills complete, land at the nearest suitable alternate. Point is, Patty, you might lose the other operating pilot too ! Much like twin engine aeroplane, lose one, you have , technically lost 50% of your power & that, is a MAYDAY. Of course, from an airmanshippoint of view, you might lose the remaining engine !
"suitable" throws the debate wide open. I regularly float past Myanamar in my two engined widebody, Losing one donk, although Myanamar is the closest, it is really not that suitable.
I think the QR FO did a great job. A full Mayday should have been declared.
Safe flying guys and heartfelt thoughts to the skipper downed in his prime. R.I.P.