Chamot's abilities are still fairly unknown.
Additionally, they don't really want to kill him/her, so it makes sense they don't go for an insta-kill.

At this point, it pretty much has to be Maura for the person who triggered the trap unless there is some out of nowhere BS.
As for why she did it, I guess we'll have to wait to figure it out. Hans' speculation about Adlet's motives could be applied to her. Maybe she has family captive or something. We'll just need to wait and see.