I don't think the Model X comes with bulletproof glass standard, which means that either Tesla found a way to screw up regular safety glass or that Chao went out of her way to replace the standard glass with bulletproof glass. Either way
They screwed up regular safety glass. It's supposed to be "tough" glass to deter people trying to break into them, but isn't actually strong enough for that (Hitting them with a bit of pipe or a brick hard enough still breaks them fine) but they're too strong to break with your fists or feet from the inside. It's like a weird anti-safety measure.