My suggestion would be; go back to Ponderosa and talk with the manager, since it didn't seem to be his idea and didn't appear to have a problem with you guys being there until "SUGGESTED" by the pd to put up a sign. I would talk to them and explain the cops were the problem and would they mind if we come back. What better way to show the pd started the whole thing (not that it isn't obvious) than to return and have lunch....WITH PERMISSION! Then when pd shows up...tell THEM...they were not invited!
ETA: This is one time I will have to agree, this needs an in you face response.