Hang on. IIRC the QRF is 'loaded' by turning against a spring one way which allows the locking plate to be free to float and the harness lugs to be pushed in. The knob is then simply released and that's it locked. It needs no positive action.
To release it's turned a click the opposite way then pressed. When it's in the unlocked it's pretty obvious because the lines don't match.
I stand to be corrected on any of this as it's well over a decade since I saw a QRF and the closest I got to Typhoon kit was the RAF SAM prototypes. (are they still called FAGOTS?)