I don't see how that's any different than the laws of physics themselves - we find ways to exploit them in useful ways, and workaround seemingly intractable problems all the time. We can hack the laws of nature without the universe being a simulation. Gravitational field propulsion is an excellent example - faster-than-light travel without ever locally even moving.
"Time slips" may not be physically real; I'd like to see some form of evidence, like somebody bringing back an antique that doesn't carbon date the right age. Until something like that happens, my preferred explanation is some kind of waking dream.
