Thank you, Swedie. I have no doubt that the coroner talked to DM directly, by phone, as that is what MEs do. They would have spoken about the initial circumstances surrounding the death of WM. I don't know that they would have talked to him when the final report was complete.
By the time of WM's memorial, DM could have told anyone anything. There would have been nothing in writing to prove him wrong. However, insurance companies often require a detailed ME's report, which is only released once all ME reports are finalized, sometimes months later. In some places, the policy is for the ME to speak directly to the next-of-kin by phone before the final report is made, as there have been some cases in the media where families were shocked to learn months later from the written report (mailed out, for a fee, on order forms sent to the kin at time of death) that their loved one had not suffered an accidental death, but was murdered.
I'd be curious to know if the coroner's report had been completed by the time TB was murdered, and if any insurance claims WRT WM had been paid out. Wait and see if this comes up in court as to motive, I guess.
Here's me thinking that the obituary was written to allay any suspicions on the part of insurers as to DM being anything but a straight-up, loving son.
Any recent policy would have been contestable, and any policy at all would not have paid out to a beneficiary who murdered the insured, IMO.