To those that say that you shouldnt be alowed to enter WDW without some limited knowledge of English, I agree. However, Disney is making it too easy for those without English to visit the parks with the Ears to the World system, translated guidemaps, saftey speils, and CMs with language pins.
Dylan, you did the correct thing IMO. If it ends up being a record card violation fight it. Saftey, then courtesy, show, efficiency. You tried to communicate that they needed to cease a dangerous activity, they did not comply. You used another method which should be completely acceptable.
And you know what? I bet that guest complained to GR in perfect English.

Edit: and yes, ucfsweetie, I agree totally. I absolutely hate when that happens. "I'm sorry, but I dont understand you." You know, we should start giving them directions to the nearest restroom in reply to whatever they ask. Or tell them they might be able to find a "llama" at Disney's Animal Kingdom. :p: