Sort of, but it's hard for me to get angry at the people who called the police in either case. Yeah, they should have more common sense, but the police are the ones with responsibility here. If you're scared you're scared, and you should be able to call the police for pretty much any reason and expect them to deal with it rationally and professionally.

In this case, if the police just show up, look at the whiteboard, laugh it off and leave, then I would say no harm done. Whoever called them feels safer, and everyone else has at worst been inconvenienced for a half hour.