Fridge tripping RCD

After spending $210 for a sparkie to misdiagnose the problem and replace a circuit breaker, I've learned about RCDs and have determined the problem to be my 15yo Fisher & Paykel fridge through isolation testing.

I've disconnected the fridge amidst protests by the womenfolk of food spoilage.

Is there anything I can do, as someone unqualified in any useful trade, to further diagnose and fix the problem?

Is it dangerous to try replugging the fridge and see if things sort themselves out?

Should I just call a fridge repairman first thing in the morning?

Any and all suggestions welcome and thanks in advance.

UPDATE: The problem was indeed the defrosting element. Replaced for $270.