As itsresidualmate said, no need to tug on the mask. Unless you're 12 feet tall you'll need to pull the mask down to reach your face. This action alone pulls out the pin to start the chemical oxygen generator. An 'Oxygen On' flag dropping down in the panel for passengers to see might be reassuring though.
My airline does not mention that the bag on the pax oxygen masks may not inflate, though I've heard it somewhere in a safety briefing. Perhaps this should be included?
This talk about an emergency descent causing ear problems - surely it's the initial depressurisation that causes that? You're going from a pressure altitude of 8,000' to perhaps 41,000' in a matter of seconds. An emergency descent is going to take about 4 minutes (at a typical 8000fpm descent rate).
Agree that a recorded message should be triggered, warning pax of a descent, reminding them to put on their own masks before helping others, and saying that the crew will provide an update as soon as all necessary emergency actions have been successfully completed. Not sure this should triggered by the masks dropping - they have been known to deploy accidentally. Perhaps when one of the flight crew takes out his/her oxygen mask, or when the FO switches the (guarded and wired) Passenger Oxygen Switch to on. (This is done as a memory item in the case of a depressurisation to ensure that the passenger masks have deployed.)
All in all, seems the Ryanair crew did everthing correctly. In the passenger's defence, you can see why they'd fear for their lives though. It's easy to criticise people (and the media), but unless you know how these things work, there's bound to be a bit of hysteria. Bet there are thousands of people out there that don't even know that air pressure drops with altitude. Plenty more seem to think that a depressurisation causes the descent as the plane falls out of the sky.