Before I jump on the bandwagon for agreeing some things to consider.
1. You said for saying one curse word. Did you intentionally bypass the profanity filter? Had you use profanities before and they warned you? Did they say something to you when they kicked you?
2. Had you been needing on gear that you shouldn't have been?
3. Were you generally being a dumb***? e.g. jumping in in front of the tank, breaking CCs, ignoring instructions?
While it is entirely possible they kicked you for loot, it's also entirely possible they kicked you for other behaviour and the profanity was the final straw.
If they were willing to tolerate him the entire FP for that and kick him before loot then they are still guilty.