At least the cannibal had the victims consent to kill him - a circumstance one should not ignore. Has Mr. Allen asked the owner wether he may steal the TV? NO! Therefore, Mr. Allen should shut up and be glad that he wasn´t punished to death! .. Ok ok, I want him out... but I have nothing to say. ;-)
a circumstance one should not ignore. perhaps not in Germany, or Scandanavia, or the Amazon Rain Forest (though, even there, it's doubtful it would be given much weight).
But in any civillized nation (assuming one can still find one) that circumstance is irrelevant to the crime of murder.