you need to listen to part two.

and we saw what happened the last time they tried to negotiate with the 4-5-6. and they all saw it too. they really didn't have a choice other then to round them up, since they had no idea what was going on jack's end.

i don't think that was on their minds though. they wanted to end it...times of crisis means rash actions. i doubt they were thinking about re-hacking into the system to see what the government was seeing. besides, i think the government was only looking at what was going on in the room, not the children.

and if i remember correctly, when jack stated that it was all his fault, he only mentioned the team. i think it goes without saying that it was his choice to kill his grandson. but it wasn't his choice for all of the others to die...he was just blaming himself for everything. that's why i only mentioned the his blaming of himself for the death of the team sans gwen. because he didn't mention steven.

oh and about the resonating the sound...they already said they didn't have a sound system powerful enough to resonate the waves. they had to use the kids again. they didn't have time to find another way.