Connection between coolant leakage and car navigation

I recently took my toyota sienna xle 2006 to a mechanic to fix a coolant leak. After the repair which cost $750.00, the mechanic called to tell me that they had to disconnect the battery during the course of the repair and now the navigation disc will not reboot after reconnecting the battery. He said it is due to natural product wear and tear and he will not pay for it. The disc is only about 3 years old. He said it will cost me $2300.00 to fix it. This is the second time this has happened with the same mechanic. The first time though, the problem was not the leaking coolant but the problem was not associated with the navigation but he still messed it up. He paid for it the first time. Can I win this case in court?

your mechanic should have used a memory saver its a small thing that plugs into your power outlet in the dash and keeps the memory alive in your radio and other things like your nav unit… youu need to ask yourshelf is it worth haven to find a new mechcanic over a seven year old nav unit find a local stereo shop that does repairs and get an estiment to fix your nav unit or replace the head unit with an aftermarket one with nav in it. the savings should be over half. far as winning in court call a lawyer. but is the cost worth it