Is there any way to communicate with the moderator about this?
As a recently-elected moderator, let me say that I appreciate your concern for keeping the site clean and in trying to understand the rules/guidelines for it! I will echo what not-yet moderator Stephen said that the site's main chat room, currently named /dev/chat, is a decent place to catch one of the moderators, and that posting here on Meta is also an excellent idea -- primarily because it's easier to search & find -- but that you could also raise a custom flag on the post to say that it is "in need of moderator intervention".
If you think the moderator simply mis-clicked or mis-understood a very clear situation, I would point you towards the custom flag, since that's a simple, direct solution to the problem. If the moderator who picks up that second flag is paying attention -- this time -- then hopefully they'll make the "right" decision, or at least hand it off to a different moderator for a second opinion. If the post is clearly spam, then that moderator can take of it with a single spam flag. Note that this is best in situations where the case is clear; flag comments & responses are limited in length.
For most other situations, I would encourage a Meta post to air out the misunderstandings. That helps the moderators, you, and future users all understand what the current guidelines are.
Third-best all around would be the chat room, IMHO. I do my best to keep up with it, but it can get busy, and even a chat-ping there could get drowned out by other site notifications.