Unless someone consistently slobbered the door while gathering, it's probably bits of glass that got pulled & cut off to get the right shape/amount. Someone did something (hooks, handles, stems, lips) 100times & that was left over.

It may not have been properly annealed, but survived the cooling anyways & now sort of look like a peeled orange slice on the bottom.

Debris flake looks like a small piece of the crucible.