You know, when I wrote it I actually questioned whether I should use the word "lying," or if doing so would cause an overly nit-picking response, but I decided to expect the best in people. Surely they'd see that I was establishing a shared premise that he wasn't lying, which is the usual opposite of "telling the truth," while pointing out that he wasn't necessarily telling the truth. There's a middle ground of ignorance.

But by all means, thank you for interjecting yourself in the conversation to state the obvious.