San Diego mayor is suing the city seeking reimbursement over his legal fees, and the city is suing him back. I can't say all that much about a general lawsuit, but there have been numerous attempts to get the state to pay for an elected official's expenses in a recall (there was a lot of discussion during the Gray Davis recall). Some states have it mandated that the state pays -- California had this, and Senator Michael Machado looked into it after surviving a recall in 1995. He abandoned the effort. It is not clear what would be paid for in any case. Similarly, the El Paso mayor just tried to get the city council to pay his $500K legal bill, which they rejected, and the Arizona legislature looked to pass a law to reimburse former Senate President Russell Pearce. That did not go anywhere either.
It'll be interesting to see if Filner actually tries to push this one.