The only problem with helicoils in this scenario is that if they aren't installed 100% correctly, then the situation is made worse.

Also - if they aren't installed correctly then you're into very big problems most probably resulting in a new crank!

Yes, i'm in full agreement that they are the 'correct solution' and i myself would indeed have recommended it be done if it had been any more 4 threads that had been damaged. However, in my experience, with the remaining thread engagement that was possible and the load spreading available, what has been done is an acceptable solution.