Despite carrying a glass-fronted gadget in my pocket for most of the past two decades, this is the first time I’ve done this:
Turns out you can’t trust a rolling seat on a slightly unlevel surface, as shifting your weight can let the thing roll out from under you with no warning. If you’re taking a picture at the same time, the phone reaches the impact point before your hand: even a nice case with bumpers all around won’t be quite enough protection.
I was tempted to leave it un-fixed as a constant reminder to not do that again, but the broken glass was rough to the touch and interfered with Android’s swipe-upward gestures.
Fortunately, the tempered-glass screen protector absorbed the energy without damage to the actual screen:
A thin plastic layer holds the protector’s fragments together; I hadn’t known it was a two-layer structure.
Being that type of guy, I had a spare protector in a desk drawer and managed to apply it without trapping any bubbles or fuzz underneath.
The Smell of Molten Projects in the Morning 
Bravo! I’ve never been able to avoid bubbles and fuzz on anything but a pristine new phone.
For once, all my blunders canceled out!