Pilot never declared an emergency.
Almost every time I see this, I have to ask... So what?
Note that a pilot doesn't have to broadcast the words "declaring an emergency" for an emergency to be declared (e.g. by the controller on behalf of the pilot). Also note that saying those three words doesn't really change your situation or what the controller can do (other than perhaps bypass a sequence line or get information ready for SAR). It doesn't make ice fall off your wings, it doesn't make an airport sprout up near your location, etc.
Based on the information contained in his transmissions and the urgency with which I'm guessing they were made, it's rather likely that all parties were aware of how unsafe the situation had become.