Local law enforcement were members of the Manhunter's private army, and co-conspirators in protecting an intergalactic war criminal. Their protocols and authority were invalidated.
People died because the Manhunter killed them, not because Hal was doing his job as a Green Lantern.
And the writing is good because an innocent character takes the blame for crimes he did not commit, for no other purpose than to affirm, without justification, the notion that the character is morally bankrupt?
Ok, then.