Big enough, yes, but there was footage of hitting it with a pretty big hammer.
I'm not saying that Tesla windshields are vulnerable from that, in fact, most windshields aren't. However it shows that resisting a blow from a hammer that is neither sharp nor hard is not a conclusive test.
The difference is in how they break. Laminated glass will generally crack, but otherwise stick together, while tempered glass will shatter, but into less-sharp pieces (to minimize the hazard of broken glass).
I don't know how much of this matters, but it stands to reason that what works on a side window might not be the same as what works on a windshield.