Because that one wasn't sentient. I think usually its kind of like in Avatar where the original person is unconscious or whatever while they operate their ganger, but that got all thrown out of whack for the people in the monastery in the electrical storm and they ended up with a conscious person and a conscious ganger. Amy has just real self (who is sleeping or whatever), and her ganger whom she is operating.

Its still kind of shaky ground though, given what we learned in this episode ... but I guess that's why whoever is using them is evil!