Judy is like most characters, has their good moments, and moments you just want to shoot them. Hell, there were a couple of times i wanted to just punch Jackie in the mouth. That's being realistic though. It shows they, V, and we, are human. Despite the fact some people are choosing to ignore it, the game has files that show Judy tried to get Ev some help, even paying extra for them to come to the apartment. Ev obviously made a choice the moment her mind was once more her own, and, following her opportunistic nature, waited until the right moment to act. V was busy with the task of saving their own life, and Judy had gone out, likely trying to get back to normal life. Ev had her chance, and she used it. The only people other than Ev responsible for her death are Woodman, and the Voodoo boys, likely Brigitte.