The two phenomena in the article are incorruptibility and responsiveness after apparent death. Granting the evidence is weak, is it possible?

Death for medical purposes is really the boundary when function is not at all expected to return. It's not when metabolic processes stop. It can vary with treatment (handling?).

For incorruptibility, (as others have mentioned) diet could be a factor, especially for immunogenic foods. Lack of stress is another. Stress hormones have wide-ranging impacts and are key to sleep, wherein detoxification, esp. reduction of reactive oxygen species (ROS) by melatonin. A monk at peace for months or years before death could have a vastly altered hormonal and metabolic landscape.

Therapeutic hypothermia is cooling the body after near-death trauma from heart attacks and drowning. In the last ~15 years, it has been instrumental in increasing survival, even for people e.g., under water for many minutes. The problem is reperfusion injury: after a bout of anoxic cellular respiration, there's a large build-up of ROS; re-introducing full metabolism quickly results in these molecules reacting with others, impeding metabolic processes and destroying some cellular structure. So cooling and only slowly reheating the body allows the ROS to be scavenged instead, and people survive as a result.

If there's validity to incorruptibility in this context, my bet would be on some combination of coolness and processes that reduce ROS, coupled with a very low population of ROS from a stress-free history before death.

But a mechanism of incorruptibility doesn't address the other phenomenon of responsiveness, holding collapse off until some signal.

In my (limited) experience with people after stroke, long after any cognitive abilities are gone, the person maintains reactivity to the environment - touch, heat, light, sound, and (yes) voices. This reflects more autonomic processes. The cerebellum maintains body awareness and position with input from the midbrain, and spinal nerves for muscle groups can operate on their own to hold position and react. (Indeed, one of the signs of the absence of CNS suppression is painful, relentless muscle spasms.) So I can imagine nerves and muscles holding anoxic positions, and even some reduced nerve signaling from the cerebellum using ion reserves. The holding would have to be perfect, and the signal to release would be a one-time thing. This would not work repeatedly or for any signal to do something.

My overall takeaway is that we don't realize the extent to which we are a product of our bodies.