terryp,
with all due respect, but as a PPL holder you should be aware about the definition of "severe turbulence".
The situation you describe was far from that. In severe turbulence, sorry for the drastic words, you would have seen people sticking in the overhead bins when not fastened on their seats. Given the fact that there were FAs at work at this time, this was far from severe.
I'm not a 747 driver, but nonetheless, you can take my word: this ugly old thing will still smile at the turbulence you're experiencing while you get bruises from your seat belt. Don't mind...
I guess there was just mild turbulence forecast in the area so the guys on the best seats decided not to overreact. When the turbulence got worse they (or AT?) throttled down and they changed altitude and direction trying to minimize the rodeo :-)
Don't take this as an offense, please. I just want to tell you: You're safer as you think you are in turbulence. When was the last time a plane threw away vital parts in turbulence (flown by a professional crew, that is...).
Kind regards,
Peter