Sure you are allowed but that is documented. In Canada if someone gets out of bed and leaves the hospital, the patient and/or next of kin are contacted. If that fails and it is determined there is no risk, the fact the patient left without announcing it is documented and it’s not the same form as the regular AMA (where patient do sign)
The above part of the scenario may be muddy but there is zero justification for the handling of the remains. This person clearly died in the hospital or close enough to be returned. How is that part mishandled for a year when they also have a patient missing??!
Also, all my respect to nurses, you are the life blood of the hethcare system. However, this is an administrative fuck up, not something nurses are expected to deal with (again, at least not in Canada). A nurse would announce a patient just walked away and it’s the job of admins and sometime social workers from there on