There’s something about the word “sure”. One time, I asked a junior associate if he had some time to help on a client project. He said, “Sure.”  I said, “Look, if you can’t do it, just tell me.”  He said, “I said, sure.” I said, “Exactly, forget about it, I’ll ask somebody else.” Later that day, a client asked me if I could draft a doc over the weekend so that he could have it by Monday morning. I said, “Sure.”