I have seen a lot of panels that had bad things done to them.
I do not recall a physically broken cell, unless the entire panel was smashed.
I saw a panel that was smashed (no glass left on the front), but still working fine. No cells showed obvious damage. I doubt it worked very long after.
If one cell was broken in a standard 36 cell module, the most cost efficient solution would be to simply bypass that cell.
I have a gut feeling...
The module output is based on the area of a cell. If a broken cell is repaired, the surface area would be reduced. The output would likely go down more than removing the broken cell from the circuit.
It would be an interesting experiment either way.
G-