I never heard of anything like that happening before. The only thing I have come across as far as a language problem is for members not to chat in another language other than english. Someone could be cheating that way and others wouldn't know, because they don't know the language. I don't think it is fair for them to not use english, if they don't know it themselves, then just don't chat or learn the simple common abbreviations like for nh, ty, gl, gg etc. etc.
Now as far as not getting paid if you place, language shouldn't matter. That'd be like gender or color mattering, it shouldn't. Let me ask you this tho. Was this player by any chance, during the game, chatting in another language other than english? If so, that could possibly be the reason. Also, did the forum or the poker site not pay it? Sometimes the forum is responsible for the payouts, sometimes the poker site is. I'd contact the responsible party and ask them why.
Best of luck!
Betty