You have such gorgeous hair!!! (sorry I could refrain myself from complimenting you).
When I read your post, I assumed that by 'free day' you meant a day without exercise but reading others' replies, I see that they interpret free day as eat-what-you-want.
I started doing BFL some time in late fall, I am probably at 12 weeks now although I don't know when I started. You see, I started to follow his suggestion of Weights/Cardio/Weights/Cardio/Weights/Cardio days followed by a free day (=no exercise but still eating on plan).
However, I have to say that from the very beginning I adjusted his concept to my needs as I am in the final stage of my weight loss and I was already lifting weight prior to starting the BFL program (I also do Zumba classes for my cardio instead of his recommended HIIT cardio).
Although I do not allow myself free days as in eat-what-you-want, I do sometimes go to have a dinner (out) with a friend when I really don't care too much whether it is healthy or not. However, those are only occasional events and I try to go back to my normal eating asap. I would agree though that if I had an eat-what-you-can day (I mean all day) I would probably eat a whole week's worth of bad food and it would be extremely hard to return to my lean diet.
So my motto is to have an occasional treat (or sin, if you will) here and there and don't worry too much about it. Life is short.