The reason why I qualify objectivity is because all information must past through our subjective perception to reach our consciousness, and therefore can never be pure. But this only matters if one wants to assert that things exist outside their own perception, and there’s really no reason to do so.

In my experience, I perceive that the sun is in the sky. There is 100% consistency to this perception, and I also have the experience of nearly 100% consensus from what I perceive to be “other beings” (allowing for a negligible number of dissenters for whatever reason).

This provides the highest level of objectivity possible for a subjective being, so we can use the word objective for convenience, but I’ll never know whether there is really a fireball in the sky, or if we are merely all deceived in some way. It really doesn’t matter, since there’s no practical difference.

As to liars, there is one lie that counts, even if the person is honest in their belief - the lie of not acknowledging a difference between certain knowledge and best guesses. It is impossible to be telling the truth and be wrong. I know I perceive a phone in my hands right now - that is truth; I cannot be wrong about that. I do not know that this phone (or anything else) exists independent of my perception.

If I said I did, I would be lying even if I believed it, because I am not acknowledging the fact that I can’t possibly know that. It’s not just being wrong; it’s asserting truth when you have no rightful claim to it. It’s an act of lying to yourself because the information is available to you by 5 minutes of logical reflection, but you are willingly ignoring it. That makes it deliberate.

Promulgating an uninvestigated claim is a lie by default. We don’t get to cover our eyes and claim innocent ignorance. We have a duty to truth.