I flagged this answer (now deleted, so I can't repost its whole text) as spam. I was later greeted by this message in my flagging history:

declined - a moderator reviewed your flag, but found no evidence to support it

Now, it looked to me like there was lots of evidence. The post was just a link to a software download page, and the only context given was that the software is allegedly the best. I had literally never heard of that software before, and the poster offered no guidance as to how to use it to accomplish the task. The link wasn't even formatted correctly, so it looked to me like the user didn't care about helping, just about mentioning the product. The user has only 1 rep, so it's not like they were around a while and well-meaning.

Clearly, the answer was low-quality, and bad enough to merit deletion (I think through the LQP queue). If flagging as spam was wrong, what should I have done with the post?