Well, he is a pretty terrible physicist then. Einstein's "theories" aren't necessarily his own theories, rather a conglomerate of prior works. The MM-experiment (its said Einstein didn't concern himself with this experiment, but this experiment proved that the Ether as was conjectured doesn't exist, because light (c) didn't have varying speeds based on position of the interferometer), the Lorentz-Transforms (Einstein utilized this in his theory of special relativity), and they don't conflict with Maxwell's equations.
And where it concerns General relativity, we utilize Einstein's work to understand the precession of planets, use it for GPS, and explain deflection of light by gravity just to name a few.
I graduated with a degree in physics as well, so tell your brother to sign his ass up and lets hash this out.