This should not be an issue, for the reasons already mentioned.
1. Guns don't fire unless the trigger is pulled.
2. The trigger cannot be pulled while it is in the holster. NOTE: I did not say 'it can't go off in your pocket' or 'it can't go off if you jam it in your waistband,' because it IS possible (though still highly unlikely)...but a proper holster keeps things out of the trigger guard and away from the trigger.
3. If the gun DOES fire without the trigger being pulled, you have a seriously defective gun, and need to get it fixed ASAP.
4. If the trigger is being pulled while drawing, you need to practice your drawing technique A LOT with an EMPTY gun before you ever carry loaded.
5. Hmmm. To be frank, and hopefully not mean or rude, I have found that most of the people who have concerns like "well, it might go off" really do not know that much about guns. Thats fine...you do what is done here on TFL, you ask questions and get educated. But I would worry quite a bit about someone in a state of relative ignorance carrying a loaded weapon, at least until they had been educated. If you fit this category, you might want to consider some firearms training courses and such before you carry. Just a thought.
Mike
------------------
"A human being should be able to change a diaper, plan an invasion, butcher a hog, conn a ship, design a building, write a sonnet, balance accounts, build a wall, set a bone, comfort the dying, take orders, give orders, cooperate, act alone, solve equations, analyze a new problem, pitch manure, program a computer, cook a tasty meal, fight efficiently, die gallantly. Specialization is for insects." -Robert Heinlein