Dylan,
Your config looks good for answer supervision so it comes down to what is the tenor hearing that makes it think the call is connected. The other issue could be is it really the tenor that is sending the connect or is the originator doing his own connect for billing without getting it from the tenor. You can check this from the event log if you were to make a test call.
As for what the tenor is hearing, well, again, you should start the event log (ch should be enough), make a test call through, watch the event log and listen to what may be triggering the tenor to connect.