If indeed your running a tight ship and there are no issues simply write (send sig requested or certified) the Animal Control HEADQUARTERS and nicely tell them your a victim of a crazy dime dropper and it must stop. Cite the past w/ case numbers and explain there has never been any citations or warnings either written or verbal when authority arrives to investigate.
I would ask them to flag the address and demand names and contact info from all dime droppers, VERIFIED, not just, THE CALLER SAID SO, I mean VERIFIED! Tell them it wastes there time and yours.
If it persists
use the Freedom of Information act on them demanding info on the dime dropper, drag his behind into court and let the judge have a crack at him. If you use the FOIA THEY WILL PROB MAKE IT STOP because the FOIA act is a VERY powerful tool. They do NOT want to deal with it. IT TAKES A LOT OF TIME. They will probably start scrutinizing calls to your address much more and if it is always the same person they might just take the call and do nothing.
I had a similar situation. After 2 trips by code inforcement they saw it was all bullogna and I have not seen them since.
ALSO, if the RED TAGGER is writting unsubstanciated RED TAGS he needs to explain themselves to you and THEIR boss in a sit down.