Where's the burden of proof fall here, JD?
Sorry Dave, I take the scientific approach. Nobody has conclusively proved anything either way about the Saudi reserves, so I remain an agnostic. Maybe they're lying, maybe they aren't. We don't have enough info to answer the question.
If you want to believe that the Saudis are lying, despite having zero evidence to back that up, be my guest. Just don't try to fraudulently pose as a scientist while doing so.
I think that's the safe position to take.

Without evidence one way or the other, the only thing we can do is create hypotheses.

One is that since the Saudi can't raise production to stabilize the market, they are upping their theorical reserves in the hope of reassuring people and calming things a bit. Kinda like saying: "Oh, you want something now? Don't worry, you'll have something good later. But for now, just trust us."

Maybe that's what's happening, maybe not. I really wish we had a way to find out, though.

Re: "so I remain an agnostic. Maybe they're lying, maybe they aren't..."

The scientific approach, OK. let's talk about that. I will spend some time on this since its important. Science involves radical claims sometimes (e.g. Plate Tectonics in the middle 20th c.) but such claims also require some initial evidence and empirical verification (via correct predictions - such claims are falsifiable). Here we get into an interesting situation. Suppose a crack (not Cocaine) team of petroleum geologists got to examine the Saudi data and fields. Suppose, based on their inspection, that it was plausible that their new reserve numbers were true. I think that would be the best we could do -- given the uncertainty -- and I would provisionally accept their claims pending empirical verification (actual production) down the line. The term "agnostic" would be beside the point, wouldn't it?

On the other hand, suppose I am told nothing and can not adjudge plausibility at all. Then I can say I have 0.5 bbo URR in my living room -- well, I won't reveal the real numbers -- and you're just gonna have to believe me or not, huh? I've got the stuff, wanna invest?
There is not zero evidence. There is excellent evidence, though not proof beyond all doubt (which we do not have the luxury to wait for). You quite clearly have not read Twilight and I suggest you do so carefully before further wasting our time. As I noted elsewhere, it documents exactly what the American companies who ran Saudi production believed when they left. There is no way to reconcile Mr al-Naimi's position with what they believed. He is essentially claiming that Saudi Arabia is going to recover more oil than the American engineers believed was in the reservoirs to begin with. Nobody has ever recovered that much oil. American oil companies may not be perfect, but they at least face serious consequences for fraudulently misrepresenting themselves to their investors. I'm inclined to believe them over Mr al-Naimi any day.
Well then, since you know from Twilight what the Saudi reserves are, why all the fuss about transparency? Why do you want to know what the reserves are if Matt Simmons already proved with his excellent evidence that there aren't any???
JD, agnosticism is not a scientific approach.  In the absense of evidence, a scientific approach requires that you are skeptical.

While it might be unscientific to claim the Saudi's are lying with only circumstantial evidence, holding a belief that they probably are would not be unscientific at all.  Occam's razor and all that.

To fail to hold the Saudi's up to skeptical challenge, in the absense of evidence to support their claim, would be utterly unscientific.

 --J