You can buy some very long-nosed pliers that may do the trick.
Silly me, I just make sure the switch is OFF and stick my hand down to get whatever does not belong. I think as long as you got the big pieces, it should probably be okay.
I seem to recall reading a thousand years ago that glass shards actually SHARPENED a disposal.
You might try calling the dispoal-maker’s Customer Service tomorrow, and ask if bits of glass would do any harm.
~VOW
Got most of them (95%+), then filled the sink with water and flush the debris down the drain.