This is why NOT the SERPA holster.
Some will say it’s not the fault of the holster. To an extent that’s true, but there have been more than enough incidents of people wearing SERPA’s and shooting themselves in the leg. The nature of the holster’s lock and thus the resulting draw just allow for such things to happen.
It’s also demonstration that “one round from a .45 ACP” doesn’t guarantee any sort of stop. Caliber is a minimal concern: being able to place the shots where they need to go matters so much more.