Yes, the first sites I was sent (and passed along to this forum) do seem to be those of ambulance chasers - but not the last one my friend sent me (which includes many follow-up comments): Unintended acceleration reports for Prius, ES 350
Forgot to say that I doubt I was "standing firmly on the brake". However, the brake pedal was depressed firmly enough (in my experience of over seven years driving this particular vehicle - 88 months, to be precise) to prevent forward creep in Drive or backward roll in Neutral.
Have been chasing the repairer to send me photos, which he says he'll do first thing tomorrow morning as it's after 5pm here now. Will forward them as soon as I can.
Thanks for posting the photos...it's really unfortunate that this accident happened to you. Good luck on getting your car restored to its original condition.