Keep the disposer off and safely isolated, and prevent anyone from using the sink. Do not grind glass, reach inside to pick out fragments or assume that removing the visible pieces clears the chamber.
What the observation tells you
Small shards can lodge where they cannot be seen from above. Running water or the motor may move them without proving the appliance is safe. Protect the surrounding work area and collect only accessible surface fragments using an appropriate safe clean-up method.
A useful next step
Tell the engineer that glass entered, including whether the appliance ran afterwards. This information changes how the chamber and connected waste path should be approached.
Manuals and supporting guidance
Model-specific instructions take priority. These references support the practical principles discussed here; they do not diagnose your appliance.