Screw-ups are inventors’ delight or horror depending on how it happens, when it happens and how it is used thereafter. Murphy’s Law says that, “What can go wrong, will go wrong.” And in engineering, it is used as a point of perfect, that the more closely anyone works to get something “perfect”, the greater the chances of errors, mistakes and irretrievably disastrous results become likely.
You can read more about Murphy’s Law at Wikipedia’s entry about it. In art, in music, in writing and sculpting, the same thing is obvious – mistakes happen. And, in engineering, science, math, creating, designing, making, building, inventing and innovating, mistakes can and do happen as well.
Knowing that errors and goof-ups happen is valuable, not project stopping.