Any perturbation of the Moon's orbit that occurred in the last 100,000 years or so (or even much much longer ago) would still be visible in this day. There would, for example, be no tidal lock with the Moon. The Moon's orbit would still exhibit a high degree of eccentricity, etc.
This would also be true if any outside gravitational force ever cause the Earth to flip. This, along with the complete (or almost complete) melting of the Earth's crust.
Can you see now why I only consider an impact causing this?
Large bodies passing nearby leave obvious and lasting "trails" in the form of orbital perturbations.