It's hardly nitpicking. We know that objects that defy what we know to be true about physics don't exist.
Respectfully, we'd definitely have to agree to disagree on that.
I'm no physicist, and I'm on the fence about aliens being here, but look at it this way: Newtonian mechanics is less than 400 years old, quantum mechanics was discovered just over a century ago, exoplanets weren't even proved until 1992, we still don't know how the universe started, what life, consciousness or reality are, if life even exists elsewhere, if the way we sensorily experience existence is typical and/or complete, what either time or gravity really is, and what 85% of the apparent matter and 68% of the apparent energy in our universe even are. Additionally, we don't even know what technology the US/Russia/China have in their black project inventories.
The unknown unknowns are hence likely to vastly outnumber science's current known unknowns, let alone the known knowns. Assuming, for a nanosecond, that aliens are real and here, a society even 200 years more advanced than our own might look like magicians to us and be capable of astonishing feats. I know that we'd be considered Gods compared to people from 1821.
That said, I've never seen anything myself that's been inexplicable, I've never seen any evidence from anyone else that I would consider to be otherworldly, the total lack of publicly available credible evidence since the Arnold sightings in 1947 is highly likely to be a sign that nothing's going on, and I don't believe a single word that comes out of the mouths of Elizondo, Mellon et al, but I just think we don't know much more than we do know, so a definite judgement is premature.