So you made a specific objection about the defendant being represented by counsel?
At worst, the judge violated a local/state rule by allowing the attorney to be present. If there were a right of appeal, then you could raise this as a ground for reversal. However, none of us were present at this hearing, so we have no way of knowing whether the attorney's presence made any difference. Since you have indicated that your presentation of evidence was deficient, it sounds like maybe the attorney's presence had no impact. In any event, when you sued in small claims court, you did so with knowledge that you had no right of appeal if something like this happened.
Is it a due process violation? Sure, arguably, but that doesn't mean you have any basis to sue anyone.

