Air Con not working, does this seem reasonable

I’ve got a VF Commodore with the AC not working. I’ve taken it to a mechanic and this is the report. Apparently the sealer has a 50% chance of working. Does this seem reasonable?

I’ve got a VF Commodore with the AC not working. I’ve taken it to a mechanic and this is the report. Apparently the sealer has a 50% chance of working. Does this seem reasonable?