My manager asked me to tell a client the delay was due to the vendor. It was actually our own mistake.

Our project went two weeks late. The truth is that we missed a step on our side. My manager asked me to tell the client that the vendor had delayed us. I said I was not comfortable with that. He answered, "It is only a small thing, we do this all the time, and it protects the team." I did not send the message, and he sent it himself. Now I feel uneasy about working with a team that does this, but I also like the job and the people.