Or maybe it's something as simple as an initial gust rolling the aircraft beyond 33 degrees, disconnecting the autopilot, followed by some PIO before a go-around?
Been flying the A320 series for 10 years+ and have never encountered, nor heard of, the FCC fault mentioned (and it's referenced without any supporting evidence.). I have, on a couple of occasions, managed to introduce a PIO myself and seen it happen from the other pilot. It's very easy to do, especially if under pressure or surprised
Just because something is stated confidently and claims "an inside source" doesn't make it true. Simplest answer is usually the most likely.