We are not machines.
We do not read every single post someone makes just in case it has a swear word.
The forum deals with a preset list of swear words automatically.
Basically though, swears might be let slide depending on context and luck. For example, if you said ''I'm not trying to be an ass'', we would most likely ignore that, if you said ''Stop being an ass'', we might take notice. I have no idea what the context of your 'ass' was, but the basic rule is that people shouldn't be swearing - no matter what other people are posting, no matter what you think is or isn't acceptable. If a swear was left alone, then the chances are it was not directed at anyone. We only really get annoyed when people try to circumvent the swear filter, there isn't really a huge problem with swears on this forum.

Health, Ammo, and bacon and eggs!
