@Builder,
I do not know what the Pillar of Defence is, and your post is confusing with two negatives (lie, falsehood). Would you be so kind as to explain further...
The point I was making was although common people throw the word lie about, it is actually a very difficult thing to prove. The person must have knowledge that it is a lie and deliberately says a lie. It can not be a failing of memory, inadequate or insufficient facts, or fatigue/duress, or any of a million and one causes where the person did not intend to lie but did not tell the truth, the whole truth and nothing but the truth. Here, calling someone a liar means you dont like their opinion. It is definitely not proof that they lie.