Take a look at this picture....the red arrows point to the "J" arm that pivots with the seat back.
The green arrow points to the stopper pin. It's fully reclined in this photo......the pin prevents any further reclining. You can see a mark on the "J" arm where it hits the pin.
The blue arrow points to the catch bracket for the spring. This is what makes the seat back spring forward. Has nothing to do with preventing backward reclining.....it looks like this spring will tighten a little further if the stopper pin was removed, and the seat reclined further back.
That's my take anyway.....
I certainly don't think it a good idea to stress these Focus seats too much......they don't look heavy-duty.