Giving Elon too much credit there. He asked a professional baseball player friend to throw the pitch. There's no way Elon could throw a pitch fast enough to break the window, probably why he thought it was bulletproof in the first place.
Unless I'm not misinterpreting, it was the chief designer who 'threw' (lightly lobbed) a metal ball at the window when it shattered.
They did later throw a 'baseball' at it that very suspiciously bounced unlike any baseball I've ever seen. Surprise surprise the tennis ball painted like a baseball didn't break it 😅
Yeah it was a metal ball that was just barely tossed against the window. From what I heard, the engineers told him not to do that, but he still did. They got a bunch of free publicity out of it, which is probably why he did it.