rapid means changing maps incredibly fast.
senior admins retain the right to change the map to whatever they wish, at any time, without needing to consult the players. things like RTV exist because admins will not always utilize their map changing rights, and will sometimes leave that to the players. other times, however, they will reserve such privlages to themselves.
if you guys weren't playing on a map very long, it sounds like he didn't like that map, and thus changed to a different one. the number of players does not matter at all.
also, points for reading the format thread and bringing up demos, however do not put links to the FTP site. those links will die, normally within 2 days. download the demos, and attach them to your post instead.