Yes or no. Static code transformation with well defined equilivency is many orders of magnitude more reliable than the error finding rate of a code reviewer.

You still review to make sure it was an improvement, and to make sure that the person making the changes didn't make the mistake. But you don't review the correctness of the transformation itself, at least not any more than you need to review the original code.

Never said that smalltalk is statically typed, I said I work with both on my job. A refactoring don't change the code behaviour by definition. I don't need someone to review my refactoring to look for errors from an automated refactoring, maybe to tell me that the refactor didn't improve my code.

Isn't this what automated unit and performance testing is for? If a refactor (or any code change) causes slippage on any of those indicators it should be flagged or rejected.