Re Hung or Hanged ~ According to Fowler's Modern English Usage ..... Hanged is the past tense of the verb To Hang. Otherwise one would normally use Hung (as in "Taken from this place and hung by the neck until etc....."). On balance and since the deed has yet to be done I think "He should be Hung" is correct. Only after someone has done us that favour could we properly say "He has been Hanged ..... and a damned good job too"
Pedants Rule OK