On beta sites, when a post gets closed without comment, Community ♦ flags it for moderator attention.
Apparently, a comment entered through the freeform close reason doesn't count:
As you can clearly see, there should be no doubt that a comment already exists on the post
Could this be fixed? I don't think it's that important -- I just have to decline the flag, however on larger sites this may lead to a lot of extra flags.