From a legal perspective it would be an easy thing for them to get affidavits from some in the congregation who distinctly remembered you getting baptized. It wouldn't be necessary for the witnesses to literally recall seeing you going under the water, but out of a whole congregation it wouldn't be hard for them to find at least one person that did.
Well I did change halls several times even from state to state and I was babtized at an "off" assembly that wasn't even really mine so it would be harder! I just think that maybe they realized that what I REALLY wanted to do was go to the JC and dish out some ass kicking! After I tossed a couple elders who thought they were "tough" off my property like so much trash! Maybe this guy should just be left alone?