Too hard to elaborate.
Since it would not be wise for the general public to think they know too much about airlines' security arrangements, I won't discuss specifics here, but so much depends upon the circumstances prevailing at the time.
It is only the crew who can judge these. My personal advice to any Captain or #1 would be to use their judgement. The only criterion is whether there is a danger to the aircraft, passengers, cargo or crew. If, in their opinion, there is such a danger, then use whatever means you have to secure the situation.
PR is not a consideration, nor are the hurt feelings of the passenger in question, his friends or relatives.
If anything is endangered, the remainder of the passengers need to see that the situation is being addressed and contained as rapidly as possible to avoid panic, or to avoid their wanting to "help". In some situations, of course, such help may be welcome and necessary, but it must be controlled by the responsible crew member. You can't afford people wading in willy-nilly and confusing an already dangerous situation.
Having restrained a passenger, my personal recommendation would be for them to remain restrained for the remainder of the flight. This may be complicated, because at all times when they are restrained, one crew member will have to watch them. If there is quite some time to go, a diversion may be desirable.
On arrival either at destination or diversion airfield, police AND airport security should be in attendance immediately the aircraft arrives on stand.
Skipper then sighs heavily and wonders what the heck to put in the MOR!
