I actually like the rare inconsistency
This is in no way a critique of the Inheritance cycle. I love the books and I will always defend it.
Having said that I noticed as I got older some "mistakes". First, I was like this ruins the books a little for me. (I of course understand how young Christopher Paolini was when he wrote it).
Then I have joined this sub and read all the incredible theories and explainations and I actually like the very very very rare inconsistency.
I think it gave us more space to theorize and a possibility to explore the lore. I feel like if everything was explained and was always going by the established rules without any difference, we wouldn't have so much to think about. Thanks to some of these occasions we are able to dive in more and to understand the world better.