You're right about the limiter, theoretically.

I can tell you I was surprised when I hit 285 in an M power which is over 40 beyond the limiter. I think I could've done more if I hadn't backed off.

BMW dealer here confirmed that for M cars the limiter is relaxed/not observed. They were also told an M6 driver called and asked how he hit 300. So there you go!

Not sure about other models. They think that sometimes "it just happens".