If I tell you something but I am actually thinking every other word to myself, am I lying or just omitting some truth?
Consider the following sentence
#1 Jehovah's Witnesses always lie about everything. You can't believe everything they say, ever.
Compare with what I REALLY was saying (bolded words are my own thought words, omitted from verbalization)
#2 Jehovah's Witnesses don't always lie about everything. You can't always believe everything they say.
Now, would I be a lying sack of spit if I were to contend that I didn't mean to mislead you, by telling you the first sentence, and saying that what I really meant was sentence #2?
That guy is a lying sack of spit if he's really a JW and should be D/F'd for lying about "Gods Organization™"
Omission of truth is no defense for lying.