When I read stories like these I thank my lucky stars I am out of the industry and prefer to take the train . I have carried hundreds of thousands of passengers and have witnessed tense altercations on board. All well handled by well trained, people oriented cabin crew. Problems never escalated and tension was defused by a senior member of the cabin crew.
We now pay these people peanuts, train them to the minimum standard required and don't allow them any scope to deal with problems for fear of litigation.
I think recruitment now is for good sales staff who can operate a door handle.
Look at all the diversions caused by an unruly passenger. A little old lady in one case. SOPs are rigidly adhered to and an aircraft load is on the ground with somebody hauled off in handcuffs.
Wouldn't have happened in my day. When the police are called, they go for the violence as their first resort rather than the last. I think the same principles apply as for cabin crew. Some instances of the use of these tasers are terrifying and I can only say, not in my name.