IMHO....
This captain and crew will reflect on this incident and consider if they could have done anything differently, this reflection is a habit for pilots ducking the slings and arrows of a flying career.
When a captain makes his decision the outcome must be fail safe
least dead, least aircraft bent.
This captains decision when it came was fire proof, it was a safe decision.
Haveing declared an emergency, an emergency descent was a logical option.
Hopefully also reflecting will be the loo smoker and the passengers drinking their own booze onboard and thoes singing ymca to drown out the emergency briefings.
Obviously these passengers had no idea what was acceptable conduct flying onboard an aircraft and if their conduct is so out of line they must be instructed what is required of them.
This conduct should be agreed at the point of charter or travel made on something less critical than an aircraft.
Clearly companies that allow ground staff to load passengers who have been drinking can expect such diversions.
It is difficult to remain employed as a captain if you cancell the flight at the sight of the first drunken boarding passenger that ground staff hoist on the crew.
It is similarly difficult to remain employed if you return to the ramp when your charterers singing drowns out the emergency brief.
Just where you draw the line and divert if you have compromised your proffessional instincts several times in the interests of getting everyone safely home is a very fine line.
This captain recieved positive information that the cabin attendent had been assulted and control of the cabin had been lost.
This was positive information that the captain needed that the line had been crossed and this situation could not now ignored as possibly other prevoius logged warning bells.
The captain quite rightly now declared a may day and landed ansap.
Such diversions will continue until companies the CAA and security get their combined acts together to protect crews and
educate passengers.
A good crm lesson in communications problems from which everyone can learn that booze and passengers and delays are an explosive mixture.