Crime scene technicians would have inspected the steps the deceased allegedly hit to prove or refute the manner of death. Absent evidence that could be matched to the injuries, that method of the injury would not be supported.
Cart before the horse: Danny has a suspect with his lawyer in the interrogation room and mentions when the M.E. rules the death a homicide. A competent detective would not interview a suspect until after the M.E. had made the ruling.
Captain Simms calls Lieutenant Gormley "Sir" at least twice during the "dressing down" event. A captain outranks a lieutenant, so Simms would have merely addressed Gormley as "Lieutenant."