Every law has the THREAT of citation or other enforcement. Just consider it a courtesy that they gave you a warning.

You don't get any due process over what "might" happen. You only are guaranteed due process against the loss of life, liberty, or property.

You've got no cause of action. You can write a letter saying the sidewalks are clear now and they were clear at the end, but I can pretty much guarantee you it will just get circular filed.