I feel that "don't lie, just omit the truth" totally misses the point. It's "rules lawyering", not being an adult as the author seems to envision it. At least that's my reading.
"Don't lie, just omit the truth" is not even close to what I said. (It could be argued that putting words in someone's mouth is a form of lying...)
If you ask me for some information that I don't want to share and I say I don't want to answer that, or it's not important, that is not lying by omission. Or lying at all. That's me protecting my privacy. Giving an incorrect or misleading answer instead would be lying.
If you ask me for some information that I don't want to share and I say I don't want to answer that, or it's not important, that is not lying by omission. Or lying at all. That's me protecting my privacy. Giving an incorrect or misleading answer instead would be lying.