Bullfighter, this is one of the more contentious issues you'll find on Glock Talk, perhaps second only to "ballistic pressure wave" threads. Since the GATE section requires fairly short answers, the first thing I'll do is refer you to the search function, which will bring you to many long discussions on this topic here at Glock Talk.
For a short answer, the point you bring up is one I first saw in State of NH v. Sgt. James Kennedy back in the '70s. Kennedy ultimately won, but it was an ordeal he shouldn't have had to go through.
The point you mention, though, is not the main reason I recommend against handloads for self-defense. The main reason is that you're unlikely to be able to get gunshot residue testing to confirm your account of the distance involved in the shooting, into evidence. That's because it requires the court to take your word, whether in the form of your loading records or otherwise, as to what was in the gun. When you are the accused, the court won't be taking your word for anything. The "canary in the mineshaft" case on this was State of NJ v. Daniel Bias. Since then, in many years of hot debate on this in the gun forums, NO ONE has been able to cite a case where a court DID take the shooter's word or records on this. (While Bias was not a self-defense shooting, that doesn't matter; rules of evidence apply no matter what the defense's "theory of the case" may be.)
There are other issues, but the ones above are enough for me to recommend reloaded ammo for training, hunting, competition, etc. but not for defensive use.