I dont think this is anything outrageous. if a man threatens the life of an innocent little boy he should have seen what was coming for him. We would probably done the samething in this country if he did not give up peacefully.maybe more high tech way, like a swap team tear gas or rooftop sniper, but some action would have to be taken to safe the victim.
Not to sound like a spelling nazis but I think you mean SWAT, aka ETF here instead of swap
BTW, tear gas is a poor option outdoors and in a way indoors. Depending on the situation, SWAT teams usually breach the obstacles, throw stunned grenades before storming the enclosed area and disable each hostage taker with 3 bullets on average in a couple of mins time window.
Tear gas is flammable if I could recall and that's big hazard when the hostage takers try to burn something in desperation.
Rooftop sniper is not always an option, especially when the hostage taking is very fluid and dynamic and the hostage takers start to harm the hostages within mins the event unfold. The advantage of rooftop snipers is basically letting the SWAT teams to do stand-off, real time albeit rudimentary intelligence, in addition to say getting the blueprint of the building that holding the hostages before planning the rescues.
Moreover, it takes a lot of training for sniper to be calm/cool and patience to disable the target with
one shot
without second chance. Sniper training in essence is tougher than the SWAT team training and you do not say "one shot, one kill" for nothing.
BTW, maybe it's about time for Gong An (Public Security) or People's armed police to purchase more taser guns and corner shots.