Hey there!
So, a while back I think they changed the name of the field from "response" to "outcome". Also, I think the "responses" fields are to track the individual responses when you have the approval go to more than one person. I've noticed that any time I chose a field that was plural, like "Responses", it would trigger an Apply to Each loop.
I think that's because there could be many responses for each approval, but really only a single "outcome".
As far as why the wrong email was sent, I'd look at the actual field in the criteria, and then the data being sent by the approver. Is there only ever one approver?
Either way, glad it's sorted out.
-Ed-