If a reader catches an inconsistency and calls you on it, you have two options. One is to admit that you made a mistake and change the errors. The other option is to find a way to incorporate those mistakes into your story.
Suppose that Sharon said something that Cathy was supposed to say. How did Sharon know to say it? Might she be more involved than others know?
What if Michael showed up in a scene at the mall when he was supposed to be at work across town? Why might this be? What happened?
Answering these questions might take your story in a whole new direction that adds excitement and intrigue. It could also take your story in a whole new direction that you don't want it to go in. Either way is fine. That's why you have the choice to admit your mistakes or incorporate them.