A 58-year-old woman is found dead in her locked bedroom in Mumbai. The body is discovered 36 hours after the suspected time of death. Ambient temperature in the room is 32°C. On external examination, rigor mortis is completely absent throughout the body. The skin shows advanced discoloration and blistering. The pathologist notes a foul odor and gas-filled distension of the abdomen. Which of the following is the most likely explanation for the absence of rigor mortis in this case?