I've heard the break-up stories as well. While I can't accurately comment on what happened then, I can say that there still seems to be some bad blood between AOA and FX.
Now I am a multiple fanboy: Daystate, FX, AOA, Utah Airguns, Baker Airguns - They are all my favorites and I hold a grudge against none of them.
But a few months back I bought a used Crown from AOA and when I went to zero the scope I was having issues (accuracy). So I broke out the chrono and found that I was getting up to 70+ fps spread over like 10 shots. So I assumed that I had been sold a used gun where the regulator was toast.
I called up AOA to discuss the issues I was having with my new-to-me Crown, and was told very matter-of-factly "All FX's do that. Why do you think that we sell so many Huma regulators for them?"
Not really what I had wanted to hear as a customer with a new gun, but we got over that pretty quickly and AOA took the Crown back for a full refund. But it let me know how AOA (or perhaps maybe just that employee) felt about FX air guns!