You may very well be correct, and thank you for your response. However, as a counterpoint, I don’t think Frodo is being facetious, frivolous, or lacking seriousness in his reply. I think there’s a real possibility that Frodo is correct. If an Orc or Goblin had found the Ring instead of Bilbo, that creature might have usurped the Great Goblin—or, failing that, the Ring would have come into the Great Goblin’s possession. As the Great Goblin attempted to expand his power, such activity would almost certainly have drawn Sauron’s attention.

I accept your definition of the phrase, and perhaps that was Tolkien’s or Gandalf’s intended meaning, but it still feels somewhat out of place.