The bottom right of that flowchart is a little scary. So anything you post, no matter how private you want it to be, can be seen by anyone that it gets re-shared to?
Nevermind: just noticed that that only applies to posts you share publically.
Nevermind: just noticed that that only applies to posts you share publically.
They could also just tell person A or repost it if there wasn't a share button, though. Just use good sense.