At a guess, the admin looked at the post, it broke the rules and was reported and that's what the admin ruled on.
As to other stuff being allowed, I'll refer back to what @red_flanders
said here and I and other mods have said countless times. It's not that other things are allowed, it's that moderation is largely done based on reports. Sure, mods will see some things and take action or let it slide, but it's reports that drive attention. If things aren't report but others are, it can seem like some people get away with things others don't, but I can tell you when I was a mod that would never have been intentional.