If the damaged unit is insured, then the owners should claim against their own insurance and ask the upstairs owner to pay the difference.
If the downstairs unit is not insured, then the owners should present a bill to the upstairs owner for the repayment of the repairs and follow that up with a claim at a local court, if need be.
I can’t see any circumstances in which the Owners Corp should be liable in this situation, unless there was a failur os common property that contributed to the damage.
It’s time for the people who suffered the damage to stop hoping that the owners corp will ride to their rescue, and get things going themselves. It’s really not that hard. The dish washer caused the damage. The owner of the machine and/or the unit where it resides is liable. Get a bill. Make a claim.
All the EC should be doing is providing written support as to what happened and who they believe is at fault. If the owner of the unit at fault isn’t insured, that’s their problem, no one else’s.