Yes, it's a bit of sleight-of-hand. Claim that you are god's channel on Earth, the only means by which Jehovah communicates his will to humanity. Then admit that you're prone to making mistakes and you don't always get everything right. You are claiming exclusive divine authority, while also disclaiming any responsibility.
In other words, if they happen to get something wrong, it's god's fault. I used to think they placed themselves between Jehovah and Jesus, but I think it's more like they place themselves alongside Jehovah.