Dorothy was an assassin of improbable accidents.  She specialized in Houses, but had other tricks and devices.  She made her living off of a loophole in the laws of The City.
Even though it was a simulation, The City was a real place.  An avatar was fragile; subject to gravity, fire, trauma.  And an avatar only had one life to lose.  Dying in The City could be as financially devastating as anywhere on Earth.  Of course there were no guns in The City, but Dorothy had her methods.  On the morning Midas was sold, her email account crashed from overuse.