you bring up an interesting question. I have to ask, are you considering legal action? IF YOU ARE, there is a case in which a DC10 operated by American Airlines hit very, very bad (extreme) turbulence and a lawsuit by the sister of film director Steven (or is it stephen) Spielberg won a couple of million dollars for pain and suffering.
And I think the seatbelt sign was on!
There are some pilots who don't pay attention to all the ''signs''...one of which is a change in outside air temp (static air temp).
I know of one incident in which the seat belt sign was ON, yet someone got up to use the bathroom...he ended up paralyzed when they hit bad air.