See this all the time on So. Cal freeways. Often times, I get the delightfully satisfying opportunity to pass these a-holes a minute or two later when their lane has stopped, and they can’t zip out of it due to the speeds of the surrounding lanes.
Only once did I get to witness a single car accident, where someone was doing massive lane switching. She was zipping around other cars, and didn’t notice that a minivan was already changing lanes. Over corrected to the right, then to the left, and did a complete 180 before slamming pretty solidly into the cement median barrier. The weird thing is that everyone else on the freeway (and we were already going a pretty good clip when this person decided that 5-10 over the speed limit wasn’t enough), apparently also saw this coming. We all slowed to about 60 and watched it play out in a big empty space of freeway before us. She was shaken but ok, and had no one to blame but herself.