Vicky has changed her mind about Bill Malloy's death yet again, apparently, even as she goes out to meet Burke in case just in case Roger did kill Bill. Nobody in the world knows Vicky is going out except for Burke and herself. It's a perfect setup for Burke to murder her if he is Bill's murderer, or even if he isn't Bill's murderer but wishes he were because killing people is so much fun.
It seems less likely that Roger killed Bill than it did at the end of the previous episode. If he had killed Bill, he would have surely had no particular compunction about killing Vicky. On the other hand, maybe he thinks killing a girl would be a stain on the Collins family honor in a way that killing a guy would not.
Assuming that Roger's story of the night of Bill's death is true, I feel some sympathy for him. Honestly, if I were the first person to find the body of somebody whom I had a motive to kill, I'd be seriously tempted to run away the way Roger says he did. After all, we'll see in episode 1156 (yeah, I know it's a long time to wait) what might happen if one sticks around at a murder scene.