I remember calling her out as the culprit as well but then:
1. They showed her on the phone with Sidwell and he was insisting that she break into Jack's safe. She was bone dry whereas Michael and Willow were soaking wet.
2. Jack caught her in his office and had her hauled off to WSB prison. I am missing something else but the timing didn't work and plus her hair was salon fresh.
3. She is a pro. I would think Drew would be dead if she were the shooter.
4. How would she even know about Edward's gun, get in/out of the mansion or know where the key was?
Now, of course these hacks can change it because they want it to be SHOCKING!