This is an ancient topic. It came up in Britain a couple of decades ago,
in connection with eyewitness identifications, and is a favorite topic in
law schoools - professors arrange unscheduled and unexpected incidents in
the classroom and then take testimony from the students as eyewitnesses.
For a more modern revival of the topic, see http://writ.news.findlaw.com/dorf/20010516.html
Regards,
Jack
"Trust me. I have a lot of experience at this."
General Custer's unremembered message to his men,
just before leading them into the Little Big Horn Valley