RAD and therapy

Our 15 yr old is diagnosed with RAD and bi-polar. He spent 18 months in RTC and TFC and came home the end of March. We receive family based services which for the most part has been good. It is the first time that the whole family gets help as opposed to just him. In or area there is no one who deals with RAD. We have had to explain to hospital staff and even crisis workers what it is. Now that school is out the therapists have decided that taking him places is a good idea. This morning one of them took to play tennis for their session. When I asked her about it she never answered my questions just said they do this with their clients it helps them to open up more and to engage with other people. Everything I read on RAD said therapy should always be done with parents present. I am just having a hard time understanding this. How will him going and having fun with some one other then us going to help him get along with us? Am I missing something? Just wondering what others think of this. Is this an ok thing is is this wrong in dealing with RAD.