Train safely, guys. Here's a cautionary tale of one man that put a round in his own leg during a pistol draw stroke. It's incredible that he's sharing his footage from the accident.
[youtube]http://www.youtube.com/watch?v=zYvAxLX6OzE[/youtube]
As mentioned in the video, Derek Grebner of Tex Grebner Outdoors doesn't blame his Blackhawk Serpa alone for the ND. But, it's difficult not to blame a device that relies on your trigger finger to release the holster's retention mechanism. I've got a Serpa, and learned the way to use it safely is to mash the retention button with the second pad of your trigger finger instead of the fingertip. This keeps your finger from curling at all and places your extended finger on the frame as the gun comes up. It feels natural and it works. This technique all but prevents your finger from coming into contact when drawing with the Serpa.
Even when used this way, though, the Serpa isn't an ideal combat holster. The retention mechanism is easily jammed by loose dirt, gravel or even snow. Should you go to the ground in a fight and your Serpa gets filled with dirt, there's a chance your pistol is going to get locked in the holster. For this reason, I've "neutered" my Serpa (by Dremelling off the retention hook inside the holster) and use it to shoot USPSA matches. I just tighten the friction adjustment screw for enough retention and it works quite well as a gun-games holster this way.
[YouTube via ITS]