I have toured a window making co. and on the assembly line,
huge 5' x 5' sheets of glass are standing on edge and an arm
picks the 1st sheet in line and pulls it over just enough for it to
drop/fall over onto a table. The table is layered with hard rubber.
In the rubber are small holes with air coming up through them.

It's probably the same idea as what happened to you, the air cushions
the fall.
Now understanding you didn't have air blowing up on the glass,
these are also HUGE pieces of glass falling over.
Amazing thing to see.