You couldn't imagine innocent people changing their stories - but it happens. So what does that say about the validity of your inference from your own imagination to the expected behaviour of other people?

I didn't see the above when I first read your comment; maybe I was busy forming, mentally, my reply, below, to the rest of what you said. I direct you to the comment I just posted, at 02 February 2014 11:49:15PM, in response to Wes_W.