If the seller knew about these fees then yes there is a liability issue here regarding disclosure. Conversely, when you purchased the condo, during your discovery period you should have been given ccrs, hoa bylaws, and all pertinent information regarding the HOA, dues, assessments, etc. Similarly prior to closing escrow should have uncovered any outstanding debt that the seller had.
If you can come up with proof that the Seller was indeed aware of these debts/assessments you may have a case. The easiest way to do this is perhaps contact the HOA to confirm that they indeed notify the seller of these debts/assessments when he owned the property. If the total is under the small claims limit then you can take him to small claims to get the balance.
I am not an attorney and the statements above are speculative on my part. Please understand that.
