His Position: Regardless of motivation, if you give a statement that is untrue and know it's untrue, then it's still a lie.
An Example: *speaker has a black eye* "I fell down."
"I know you really got into a fight, but I'm going to let it go anyway, because it's not worth the bother of filling out the paperwork."
"I knew you'd say that."
The Question: Who do you think is right?