Suspicion
Wow,
Folks are ready to hang at the drop of a hat! One suggestion was to get all the facts THEN ACT. It seems you have done that. The "cop" left his info with a witness. HE HAS MET HIS OBLIGATION. Sounds like he made a good faith effort to advise you of his ID. Anybody can "perhaps" him into next year...this does NO GOOD ("perhaps" the witness agreed to relay the info because he knows the owner and was going to see him at the baseball/football/basketball game). We "cops" give folks the bennefit all the time during followup investigations...we have to! It sounds like you understand this and appreciate the effort made.
I am all about BBQ'n anybody who lies to avoid responsibility in a hit-and-run (I do it frequently). Most times with the average Joe/Jane though (yes, off duty police officers qualify) it is black and white. Folks either flee as fast as possible or they make a reasonable attempt at leaving info. Sounds like the ladder in this case. My offer still stands to get you the nose piece I have (I believe its pretty clean).