Very good thread Koshachey.
The one thing that I hate about BF3's chat system is what is there one moment is gone the next, and we're sort of out of luck once it's gone. Source engine games have the luxury of being able to recall chat quickly and efficiently. We don't. The other issue is that most of the admins are here to play first and admin second. The admining comes into play when we notice things. We don't go on witch hunts looking for trouble. I will be the first to admit that things have slipped through my fingers due to a playing spree where I'm doing very well and completely into the game. It happens from time to time. I do my best to keep an eye on chat, but none of us can admin what we don't notice. If I notice it, though, I'll be the first to speak up and the first to resolve the issue.
I have noticed something in our servers. It seems to me that people usually KNOW the rules, but they simply choose not to follow them. How do I know this? As an example, you have someone using foul language, I warn them. They question if I am admin. I say yes. At that point, one of two things happens: they go back to playing and don't say anything else, or they curse at me again (either out of spite or questioning/pushing their limits). This results in a kick. Usually, that's enough to take care of any additional issues for the next game or so. Sometimes it isn't, but that's what I've noticed when I'm on.
I haven't been on vent lately due to my current job situation, but getting on vent and talking to us is the most direct line of communication between members and admins. It will get our attention immediately and without a doubt. At that point, I don't know of any admin that won't take care of the situation. Sometimes, we just simply do not know that an issue is occurring.
This isn't an excuse for negligence. This is just what I've noticed in servers. As I said, if I see it, I take care of it. If I see something in chat, I will warn for it (or k/b depending on the offense.) If I don't see it though.... again, not an excuse, just sort of a real world look at what admins, especially ones that have been here a while, do while on server.