He could just about empty one 10-round mag and then pop in another in seconds while having the other handgun ready in case someone tried to jump him. When the tactical claims are bogus, you know there is another agenda here.
Yeah. They admit that he swapped mags frequently, so mag size was irrelevant.
“Investigators are aware that frequent reloading is common in violent video games because an experienced player knows never to enter a new building or room without a full magazine so as not to risk running out of bullets. This has led them to speculate privately that this might be a reason that he replaced magazines frequently.”
Exactly how, if he holds the reloading weapon in one hand and the new magazine in the other? He MIGHT hold both the magazine and the second weapon at once, but he could not easily use it for defense if he was. (Tried it here in my living room, with no stress or rush. Wasn't easy, and certainly led to moments where I couldn't defend myself easily for a moment or two.)