Said it before and so I'll say it once more;
FDs are a great tool. Like any tool they need to be checked and used correctly and, sometimes, not to be trusted. Treat them as an aid and remember what Uncle Ronnie Reagan used to say, "Trust, but Verify".
Reverting to an earlier post on a different thread and at the risk of being (am) redundant;
When being told to "follow the command bars", the reply was "those are suggestion bars, I'll do the commanding thank you".
This is an example of what I mean: