Actually the statement was, in context, everything we know about physics, not that we know everything about physics. Even then, as physics is a branch of human knowledge, and is the creation of humans, we must know everything about physics, as physics is our created pool of knowledge. So, we must know everything about physics. In other words, we must know (not that any individual knows the entire sum of physics) all of that which is in that pool of knowledge which we filled in the first place.

What is false is: we know everything about the nature of the universe, or the subjects of physics. This isn't BS, it's epistemology.

Before the first nuclear bomb was exploded, quite a few scientists were convinced that the A-Bomb would trigger an atmospheric chain reaction, and destroy the earth.

As MarkHirst conceptualized, there are far greater energy interactions occurring throughout the universe, on a massively greater scale, and billions of scary little black holes don't seem to be created from these interactions.
;-)