The whole "getting into the turn lane early" thing takes a little finesse and judgment. There are often times when the official "opening" is ridiculously far forward, which practically necessitates an early entrance. But you have to then watch for people who have been waiting to reach the official opening and make sure they don't slam into you. And of course you have to double check to make sure nobody got into the lane even earlier than you and is zooming past.
Double line or stripped legal passing zone?
To be fair, it was a legal passing zone. Their move was still illegal, however, as they were running approximately double the speed limit once we hit the 25 zone (which was about 2 seconds after they passed me).