13 Minutes : Pervitin as a truth serum??????

Okay so I'm just a history buff, but not a biochemist so please anyone correct me if I'm wrong in this assumption: Why the the world would Nazi doctors use "Pervitin" as a truth serum? I'm of course referring to the scene where Elser is tied down and then injected with "Pervitin" by Nazi doctors as a truth-serum drug, in the hopes of getting him to "confess" as to who the co-conspirators were to his assassination attempt.

Now, for those not in the "know", "Pervitin" was the brand name of methamphetaminei.e., "crystal meth". Yes, the Nazis did use that extensively during the war, but it was obviously used in order to keep their soldiers awake, and to increase their stamina. I've never heard of methamphetamine/Pervitin being used as a truth serum. Now I know what I'm about to say for a fact, because a "friend" of mine that was under the effects of methamphetamine basically stated that whilst he would ramble on and on about various topics for hours on end during its effect, he still definitely had the ability to lie when and if he wanted to (which was on quite numerous occasions).

So my question is, was this just a error/total screw-up in the scriptor was there some bizarre incorrect assumption in the 40s that methamphetamine could be used as a truth serum? I would probably have to guess that this was just a factual error, as if you look on the Pervitin ampoule label in the film, it lists its chemical formulation as: "Phenyl-2-Methylamino-propan-hydrochloride" but the formulation for Pervitin (methamphetamine) is: (RS)-N-methyl-1-phenylpropan-2-amine.

Anywaythat just really really bothered meand wanted to know if anyone could enlighten me on that subject!

Thanks!!

It really was meth according to Unholy Alliance: A History of Nazi Involvement with the Occult by Peter Lavenda. The way his eyes dilated also suggests it was meth. I can only guess that "truth serum" wasn't a well-developed technique at that time. There was that scene where the interrogators were instructed to "use anything our scientists have come up with" (or something like that). Since the Nazis were heavily into meth (including Hitler himself), maybe they used it from force of habit without putting sufficient thought into it. Or maybe Nebe really was covering up for him.