Sure there is. Glock 21. I think he mistook the USP 45 as being 13 and was saying that Glock, HK, and FN have models that have 13 or more. Just a simple mistake.
Do I think you need more rounds? No. But I had a great convo with a patrol/SWAT officer once. "In all my years of responding to incidents, many of them self defense, I never once encountered a person who said, "I wish I had had fewer cartridges in my magazine"."
Know the status of your weapon
Keep your muzzle oriented so that no one will be hurt if the firearm discharges
Keep your finger off the trigger until you have an adequate sight picture
Maintain situational awareness