What are the Limits to Powers of LDS “Prophets, Seers, and Revelators”?

I. Does it Matter that Hinckley was Counselor, not President, at the Time?
Maggie, annoyed at my post on LDS Mormonism, said…

For starters President Hinkley wasn’t even Prophet or President of the Church when this “forgery scandal” happened yet you still try to say he was president and prophet of the church. That doesn’t make a valid argument to me. President Hinkley didn’t become Prophet till the 1990s so this 1981 thing about him is impossible to be real. You are hopefully just sadly misinformed about our leadership, because the only other explanation is that you are creating this for your arguments against the LDS(Mormon) religion.

To begin, the incident is well-attested historically. So the option that I’m making it up to discredit LDS Mormonism is wrong. And what’s more, it goes against my whole point in the original post: that Mormons aren’t this big scary group secretly trying to undermine Jesus Christ. They’re generally well-intentioned people who get certain, very important, things wrong. As it was, I think both Maggie and I were sadly misinformed about LDS leadership – I was wrong in thinking that Gordon Hinckley was head of the First Presidency before he actually was; and she was wrong in (apparently) not realizing that Counselors to the First Presidency are still called “President” and regarded as “seers, prophets, and revelators.”

Here’s what happened. I was aware that Hinckley was the Mormon leader who was particularly bamboozled by the Hoffman scandal: what I wasn’t sure of was whether he was already LDS president. So I did a sloppy Wikipedia search, noticed that it said things like, “These fooled not only members of the First Presidency — notably Gordon B. Hinckley — but also document experts and distinguished historians” and “In 1983, Hofmann sold to the Church, through its then-de facto head Gordon B. Hinckley, an 1825 Joseph Smith holograph letter confirming that Smith had been treasure hunting and practicing black magic five years following his First Vision.” In retrospect, these aren’t clear “Hinckley was president” statements, but that’s how I read them at the time, so I went with inaccurate information. Mea maxima culpa.

Here’s why it’s irrelevant. From Wikipedia again, this time the article on the First Presidency:

Like the church president and President of the Quorum of the Twelve Apostles, counselors in the First Presidency are referred to by the title “President”; he and his counselors are referred to as President Thomas S. Monson, President Henry B. Eyring, and President Dieter F. Uchtdorf. All members of the First Presidency are sustained by the membership of the church as prophets, seers, and revelators.

Or, if you don’t want to trust Wikipedia, here’s Dieter F. Uchtdorf, Second Counselor in the First Presidency, referred to as “President Dieter F. Uchtdorf,” and saying things like:

It is proposed that the First Presidency sustain the counselors in the First Presidency and the Twelve Apostles as prophets, seers, and revelators.
Please manifest it.
The First Presidency will be seated.

So even in 1981, Gordon Hinckley was, as Counselor in the First Presidency: (a) properly referred to as “president,” and (b) considered a prophet, seer, and revelator. So the argument still stands in full. So the statement “President Hinkley (sic) wasn’t even Prophet or President of the Church when this ‘forgery scandal’ happened” is a bit misleading.

Finally, if you don’t like the evidence I’ve presented so far, I offer two alternatives. One, perhaps pictures are more to your liking. Two, Google it. See what you come up with. And if I’m wrong on something important, by all means, let me know.

II. When Are LDS Prophets Allegedly Immune From Error?
Next, Mark asks:

“I realize that prophets are psychics, but if they can’t tell God’s ordination of a successor through Joseph Smith from a forgery, how can they tell when God is speaking to them at all?”
Even our saints and prophets have their times of darkness. Even they have questioned the very existence of God, no? We can’t be one to judge such.
PS: But I DO appreciate your time into it and research.

Obviously, that should say (and now does), “I realize that prophets aren’t psychics…” And it’s true that prophets and saints aren’t perfect. They sin, make mistakes, have errors in judgment, etc. They aren’t just generally immune to being swindled. But at the same time, for someone to be considered a “prophet, seer, and revelator,” shouldn’t they be able to tell when they’re about to promote false doctrine? The prophets of old sinned, but they never got confused over what was God’s message and what wasn’t.

The answer to this question may best come at the hands of an LDS Mormon him/herself; as a Catholic, I’d say that when someone is acting in regards to faith and morals, and on behalf of the Church, it’s more likely to fall into an infallible (or in this case, prophetic/revelatory) category. Lots of popes have had errors in their private judgment, and there have even been errors in non-infallible papal declarations. But Mormons obviously don’t use Vatican I criteria for knowing when the First Presidency is acting on behalf of God, and when it isn’t: what criteria is used, I am not sure.

One thing to consider, though: after it was leaked that they’d been secretly trying to buy documents which shed negative light on them, those involved took to the pulpit to declare that these things which (a) were specifically created by Hoffman to embarrass and discredit the LDS Church, (b) seemed to contradict LDS teaching, and (c) were being purchased in secret, were, in fact, completely compatible with LDS teaching. At least by the point that they were ready to preach on them publicly, one would assume that any sort of revelatory or prophetic gifts who prevent them from being duped so publicly on an issue of faith.

But more obviously, and perhaps there’s not a diplomatic way to put this, but if they can’t tell which allegedly-old documents people claim to have found are authentic, there’s not really a basis for their religion. Because if, despite being “prophets, seers, and revelators,” they’re wrong on Hoffman’s “find,” how do we know that they aren’t wrong on Joseph Smith, Jr.’s “find”?