Recap
state1
It does your rotate, get rotation, then float compare. If everything aligns, then goto state 2
State2
It does your rotate, get rotation, then float compare. If everything aligns, then goto state 1
Whats happening is its able to do everything in state1 then transition to state2 then transition to state1, so its an infinite loop.
Quick way, use iTween Rotate To. Set the vector rotation and then add a time like 2 seconds. Use loop type = Ping Pong and it should do what you want. By setting the time you are requesting that the rotate takes 2 seconds to complete.
Eventually you should transition to something like DoTween.
Its a bit more work to setup but much faster and less intensive tweening system.
http://dotween.demigiant.com/download.php There are free actions and paid actions also listed on the site.