Way to go! Would love to see what was written to back em off.
But the larger question is, why does a group need to be tax exempt or file paperwork?
Well, did not want to let the cat out of the bag, but what difference could it make now ? You can access via the web the actual manuals the IRS agents have to use to review cases. Those manuals let you know how to correctly make your case. In other words, they could not refuse my letter because, just like Paton when he went to battle with Rommel, I read their book. Without reading their book, my letter could have been deemed to not meet their requirements for penalty removal.
Concerning groups, anyone that accepts payments or revenue needs to fill out paper work. Even hobbyist are technically supposed to report their hobby income, if any.