I have heard it suggested as a possibility that DM may have jumped into WM's bed, laid behind him, holding WM's hand inside his own hand, to pull the trigger - thereby getting the right angle. (For a left-handed shoot - which, even though we have not apparently heard whether WM was left or right handed, we do know that DM is). It is certainly plausible? The drug makes sense too, however it would have to be a drug that would have been prescribed to WM, otherwise, it would have been more evidence to come under suspicion, which would be undesired?