Sure it's a problem if that code ever needs to be fixed or maintained. Or if it irreversibly alters data in a way that the "coder" didn't understand or intend.

Sure it's a problem if that code ever needs to be fixed or maintained. Or if it irreversibly alters data in a way that the "coder" didn't understand or intend. If it's a prototype or some kind of one-off with limited side effects, I guess there's not much risk.