Ah but then there is the phrase "let him cook," which tends to be used when someone starts doing something that seems foolish. I would think it at least somewhat relates to "cooking." If you fail, you are "cooked."

Edit: To clarify, this phrase is commonly seen after someone says something like "hey, don't do that;" I did not mean to imply the phrase itself has an inherent good/bad connotation, merely what has been pointed out that they want to "wait and see" the results before making judgement.

I thought it was recognizing that the person acted/spoke their conscience, more or less

Shaka, when the walls rizzed.