Anyone else catch this? You can break one more monitor even after getting the Break TV achievement.

Doesn't surprise me, they probably took it a bit easy on the player in case they can't figure out how to break one or missed one of the more obscure ones.

Haven't actually gotten this achievement yet. Trying, but not yet.

Are you referring to the monitor in the conveyor belt room?
I kind of think I tried to use that one for the achievement and discovered it doesn't count as it's not a "test chamber monitor," being in a BTS area. I dunno though, I have the achievement now so I can't test it again.

I liked breaking that one though. I think it was Wheatley's calm response upon doing so that made it my favorite: "So ... I'll take that as a 'No,' then?"

Well, it's just "one" extra monitor, it doesn't really matter.