I'm really shocked to hear someone on the ABA helpline said this because there's a section in their book they give u when u subscribe about breastfeeding and cosleeping safely! I'd definitely be letting the ABA know that you were treated in this manner by one of their counsellors, sounds like this person needs some additional training!
Have a little look at the opening post again it wasn't the ABA helpline that gave this advice. The ABA won't give advice on sleeping arrangements, they are there for breastfeeding support.