I doubt if it is a small gap in their understanding that causes them not to see how they are hurting themselves and the people around them in an indirect albeit unconscious manner.
I think it is for this reason that the Buddha advised his followers to practise restraint from telling untruths and indirectly to cultivate an unwavering integrity within themselves. So that when someone point out our mistakes, we cannot hide behind excuses but are forced to face our real intentions. Sometimes, that can be painful as we are forced to unveil our concealed motives and acknowledge our hidden desires.
I find one of the tricks we learn as humans in order to make it easier to commit reckless, unethical and selfish actions is to hide our true intentions from ourselves and others. It is perhaps a reason why our parents get very upset when we first start to lie as young children. Sadly, I learned that we never truly stop lying even as adults; we just get more sophisticated with the process. We hide our intentions, obfuscate our desires, masquerade our selfish actions with layers of excuses and convoluted reasoning. Until, one day, our mind is totally ensnared in an entangled web of intrigue and confused. And finally, the original motivation for our selfish act is forgotten. (Incidentally, I think what the woman in the video really wants is attention. If the nail is removed, she won’t have any excuses to seek more attention and sympathies).
When to give advice? Perhaps, an appropriate time and situation but, I think, the most important factor is the person being advised. They should be people of integrity who are willing to look into their mind and heart. They should be willing to identify their mistakes, errors and problems with honesty. Otherwise, I feel we should just let them be. Meanwhile we can learn by observing the process of karma as it unfolds; especially develop insights into why doing things in a “wrong” way really is bad karma. (I believe, sadly, the woman in the video will eventually find herself all alone..... the very thing she wanted to avoid).
Observing how things unfolds with these people and where their lives lead will in turn strengthen our understanding of karma and the Dharma.
Appendix I:
This is a follow-up on why “we cannot hide behind excuses” but must “face our real intentions”. The principles of the Zen tradition is often summarized in the following words: 教外别传,不立文字。直指人心,见性成佛。
My translation: Do not teach those who have no faith or do not believe in karma or the Dharma (教外别传). Because these teachings go beyond words (不立文字). The teachings point out the mind’s true nature (直指人心). Unveiling the mind, one sees its Buddha’s nature (见性成佛). (I admit that I deviated somewhat from mainstream interpretation especially the first half in order to fit into the context of this question).
I believe there is a pre-requisite for the Dharma to reveal our mind’s true nature. Firstly, we must be willing to constantly observe, see and acknowledge our true intentions. Because in the law of karma, it is our intention at the time we act that determines our karmic fruits; not the subsequent intentions, excuses or reasons we assign to those actions to masquerade, obfuscate or cover our tracks. Yes, we can try hiding behind excuses but it doesn’t change the karmic consequences one bit. Knowing this, we naturally strive to avoid all evil doings and support all good deeds. Furthermore, as we understand bad karma arise from bad intentions which has its roots in greed, hatred and delusion, we try to keep our mind free from these taints.
And this sums up the practice of the Dharma: to abstain from all evil, to cultivate good and to purify one’s mind. It is kind of paradoxical that faith and belief is a necessary factor for a person to begin this spiritual journey. But without faith or belief in karma and the Dharma, we would not be willing to start paying attention to our true intentions. I find this practice goes against the flow especially at the beginning.