This is so interesting. As a massage therapist I quite often take referrals from a private physio in our group of local therapists, and wish there was more opportunity to work together. Our view (our Therapists' Group) is that yes - the massage therapists cannot diagnose, but the physios can, but economically, as their hourly rate is much higher than we can command, it makes sense for a physio/chiro to pass on the ESSENTIAL soft tissue work, with comments and instructions (sometimes just via the referred client, sometimes we converse (with the clients' permission)).
What is the point of putting the skeletal frame right, without helping the soft tissue to realign and support it?
It seems one of the other main reasons for the failure in many parts of the NHS system (apart from the huge issue about evidence-base dicussed above) is the total lack of proper holistic approach and everyone working as a team, instead of throwing up inviolable professional boundaries where anyone outside of your particular fence is an enemy! (acutally, sadly this applies to many complementary therapists as well.)