Hospital Liaison Committees, far too often, are there to run interference between Dr and patient, and to exert undue influence on the patient, which is what happened in the Éloïse Dupuis case according to a previous article, in spite of compelling evidence that she didn't fully agree with Watchtower's no-blood policy.
There are a hundred ways to browbeat someone into doing something, then claim in the end that it was all their decision. Watchtower and it's appointed Elders are expert at it. (You wouldn't want to disappoint Jehovah, would you? It will be like going to sleep and waking up in God's new world, where you will live forever. If you violate God's law on blood you would be giving up everlasting life; you don't want that, do you? Etc)
When a patient is in a weakened condition it's much easier to manipulate them.
If HLCs want to transfer information to Drs regarding procedures, or to put them in touch with other medical staff around the world who are more experiened, fine, but HLCs shouldn't be allowed anywhere near a patient.