I think there's an impossibly thin line between making glass that's easy to break through on purpose, but hard for a high speed head to break through in an accident.
I'm fairly sure that the two lines are way past each other, on the wrong side. The force with which you'll be flung against the glass is much higher than what you can punch.
It's worse than impossibly thin. It's a massive gray area of acceptable solutions where no matter where in the area you choose some bike shedding jerk will be able to construe it as though you chose wrong.
