Blimey I thought this was a university law question but it clearly isnt
Long post asking if P were acting with his professional duties. The duties being towards M ( almost exclusively ) and I think it is pretty obvious that P was acting in M's interests even tho it really irritated D
Much longer answer:
the doctors are generally governed by the regulators rules which are here
http://www.gmc-uk.org/static/documents/content/GMP_.pdf
I have been thro it and I think P acted OK
ref7 gives even more exciting stuff about end of life care which I havent accessed but which will be on the GMC site
Good reading
D's legal duties are to collect M's assets and pay debts and the usual a ( winding up the estate ) and then distribute the estate according to the will,
and quite frankly I think she should get on with it
without being sidelined on this long exhausting quest
unless of course the last will differs substantially from the longstanding second last one
which is an answer i knnow to a queston you didnt ask