Its based on who ever does the latest action.. Since technically you viewed that page at that second, you were doing the most recent activity which put you at the top of the list.. the only way you will see you self go down in the list is if the server is really loaded and A) There are lots of users who accessed pages at the same millasecond as you or B)You catch the server off guard and it didnt register you.. But thats if I think thats how it works, look at the time stamps.
I know at TWCC on the userlist at the bottom it shows your first just because its you. lol