Americans! Here are two linguistic constructions that really irritate me when you use them in a formal context!
Bad is an adjective, not a noun. Stop saying 'bad' when you mean 'mistake'. This is fine in "Buffy the Vampire Slayer", but comes across as childish and insincere when used in an apology from a multi-billion-dollar company.
Good is an adjective, not an adverb. Correct: "The performance of the code was good". Incorrect: "The program did good". Unless, of course, you mean that the code performed some moral and improving acts for humanity.