That sucks. I see nothing you did as wrong.
As much as I hate seeing people that speed all the way passed everyone to merge in at the last minute, there's nothing illegal about it(aside from the speeding part). I've even been known to do it myself. If they wanted you to merge earlier, they should place a patrol car farther up the roadway.
Realistically, the fastest way for traffic to move in a situation like that is for everyone to use up both lanes and alternate cars where the lanes merge. But, knowing the mindset of the average driver and how everyone wants to be in front and refuses to let others in, that's never going to happen.