finding that one of the phrases actually made sense in another language would be very strong evidence for the existance of God

Or maybe that they already heard the phrase (in a movie? at an airport?) and somehow it stuck in their memory, even if they don't speak the language.

Proving that it was nonsense would be harder-how do you know when you've checked all the languages?

And even if you did, someone could still claim it is some extinct language from thousand years ago, or a secret language of angels, or perhaps the text is spoken backwards, or...

Does something like "koriata mashita mashuta amon hala" mean anything in any language anyone here knows? It sounds somewhat Japanese to me.

Google Translate says it means: "Huh beneath Mashuta Amon was Korea". Definitely a revelation... or someone watching too much anime.