I've noticed that the meaning of "lying" has changed recently from what I would interpret - that lies deliberately misrepresent a fact, for the speaker's benefit, to avoid blame for something, or to make someone believe something that you know isn't true. Saying something untrue mistakenly is not lying, neither is using a euphemism or softening a statement that would hurt the hearer.
The latest I saw is a Facebook post, headed "Your music teacher has been lying to you... " which has a list of "Things they say" with translations, for instance, "What they say = “Ooh, that’s a fancy phone”. What they actually mean = “If you spent as much time on your instrument as you did on that damn phone, you’d be a much better player” "
Now I wouldn't call that lying , I'd call it a guilty conscience in the hearer if they think that was was said was not what was meant. Most of the other examples of "lying" in that post were of the teacher being tactful in their criticism instead of verbally smashing the pupil into a bloody pulp. That is not telling lies.