[pnf]

Could be, but I hesitate to say that suggests he's deeply mentally ill. It seems pretty natural that one would develop a relationship with the warden. His position is somewhat paternalistic, if you think about it. Long-time wardens may not be a thing so much any more but they used to be a trope in American mythology. Death row inmates don't tend to be as violent as gen pop in prisons; that would obviate reasons for the wardens to be severe with them.