Funnily enough I've had the joyful experience of having a glass bottle lobbed at my head that didn't smash!
I had similar drinking outside Jack Straws Castle on Hampstead Heath decades ago when it was a pub, when some lovely chaps came driving past slowly and hurled an egg at my group. It hit me with some force full in the chest - and didn't break. It bounced off and broke on the ground. Waste of a good egg.