Not to resurrect this, but I was "playing" with my P2000 and am continuously amazed at the gun's quality and engineering, and have always been a fan of this feature. As others have noted, mine has always done it successfully, and I have no fears about it not stripping a round of successfully. I certainly don't consider it a problem for my carry gun, as it IS an HK after all.
What I will say, though, is that I believe (with no evidence) that it was HKs way of replicating the P7's slide-release feature with the grip safety without any external mechanisms necessary to accomplish it. And odds are, if you're in any type of 'combat' situation and need to reload, you're going to be ramming that magazine home. Granted, their slide-release levers are the easiest in the industry (in my humble opinion; I also don't own a Sig, so please forgive me), but it's another point in HKs column.
Also, the fact that other German guns do it (I would say) points to it being rather well-understood and quite intentional, despite any legal disclaimers.