Simon's Alignment: True Neutral with Chaotic tendancies
(because tendancies are just so cool). He pretty much keeps to himself, he doesn't go out of his way to support The System (lawful) or the rights of The Individual (chaotic), but in some small ways he is more interested in the workings of people an a person by person basis than organizations as a body, whole. Towards the end, his chaotic tendancies become a bit more pronounced when he decides to 'take down the system' but this is a reaction to a situation rather than part of his personality on a deeper, core level.
Would I shift his Alignment?: No.
He doesn't undergo a change in central behavioral tendancies, he just responds to a situation. If certain things didn't happen to him first, than he wouldn't go out of his way to bring down the system, etc etc.
Is the sacrifice of the corrupt cop an evil act?: No.
It is a neutral act - the cop that was sacrificed was in no way innocent. He was a toady for the corrupt DA, who willingly sending people to prison that commited No Crime. Additionally, the purpose of the sacrifice wasn't an evil or selfish one - the point was to remove an evil organization by expediant, magical means. It's not a Shining Beacon of Goodness and Light kind of act, but by the same token, Simon isn't doing it to attain some pinnacle of personal power, or enslave people to his will, etc etc. Not evil, not -really- all that good.. leaves it Neutral.