The article's headline is misleading. The autoblog article does not mention crashes, and the cited AAA article itself says:
For example, among sites where posted speed limits were raised, the crash rates increased at some sites but decreased at other sites after implementing new posted speed limits. Similarly, the direction of changes in crash rates varied among sites in the same state where speed limits were lowered.
The only clear conclusion they were able to draw was the obvious one: If you raise the speed limit, speeding citations decrease.
Crash rates could be more related to weather conditions in some places, so it's not really surprising to see those didn't increase in some places where that's not as prevalent.
For example, among sites where posted speed limits were raised, the crash rates increased at some sites but decreased at other sites after implementing new posted speed limits. Similarly, the direction of changes in crash rates varied among sites in the same state where speed limits were lowered.
The only clear conclusion they were able to draw was the obvious one: If you raise the speed limit, speeding citations decrease.