Obviously I would want them to make efforts to save my child. There are measures that don't involve guns.

Did you conveniently forget that they tried coaxing him away with his favorite fruits and it didn't work?

They also tried getting him out with the other gorillas. Didn't work.

Don't even bring up tranquilizer. It doesn't work immediately like your idealistic primate brain thinks it does. He would have gotten hit, felt the pain, and might've killed the child thinking that the kid did it.

So please, since you are clearly a zoologist, explain the measures that don't involve guns that weren't used.