Seriously - what was it that scared Gandalf to look more into Bilbo's ring?

[Rune Son of Bjarne]

Originally Posted by William Cloud Hicklin

Tolkien nods here; because he also has Gandalf say [paraphrasing] "At first I thought it was one of the lesser rings, not such a big deal though still perilous for mortals in my eyes." I think he should have stuck with this line and not used the other, which creates the plot hole.

That would have been preferable. I have spend so many hours pondering what I had overlooked...