Tenant lied in court about security deposit amount and was awarded double the false amount, what can I do?

I had a tenant for 5 years on verbal month-to-month $700.00 lease. Tenant moved out and left no forwarding address. About twenty days later his son sent me a letter telling me to return the security deposit to his address. I called the tenant to verify that it was his new address and he never called back. He then took me to court and lied about the amount of the security deposit. He claimed to have given me $1,600.00 and was asking for twice that because I did not return in 30 days. I presented the judge with copies of monthly checks for $700.00, including the original move-in check which was for $1,400, the guy admitted he only gave $700.00 security deposit. The judge later awarded the man $3,200! I am extremely confused and upset, what can I do about this? Thank you!