I think thats probably occured becuase Richard edited his post after blackinwhite had posted. Some would consider this a bug, I'd personally probably call it a feature.
It's probably possible to put some code into post_info.asp so that on an Edit the time is not updated.
I agree with Gremlin. I admit that this can be rather puzzling though. One of these days someone here decided to edit a message he had posted quite a while ago, and that post was in the middle of a rather big thread. It took a while to find out what had happened
actually in this case it was because blackinwhite's post hadn't been approved yet, but he edited it and editing it updated the last post info, even though it was still unmoderated.