Do you mean dangerous in the sense of an accidental discharge? If so, then that's not a concern with the 1911 design.
There are 3 common conditions of carry for the 1911:
• Condition 1: Chamber loaded, hammer cocked, thumb safety engaged (AKA: "cocked and locked").
• Condition 2: Chamber loaded, hammer uncocked, thumb safety not engaged (the thumb safety can not be engaged when the hammer is not cocked anyway)
• Condition 3: Chamber empty, hammer uncocked (slide must be racked before the pistol is ready to fire).
Condition 3 is safe because it is impossible for the gun to fire without a round in the chamber. However, it is also the slowest into action, because the slide must be racked manually before it is ready to fire.
Condition 2 is safe with regard to accidental discharge while carrying, but is more prone to accidental discharge while making the gun ready to fire (i.e., while thumb-cocking the hammer, which is somewhat awkward to do with a 1911).
Condition 1 is safe (even though it looks dangerous, what with the hammer cocked and all) because it would take nothing short of a miracle for it to discharge accidentally while carrying it (several mechanical barriers to this would have to fail simultaneously, which is about as likely as the sun not rising tomorrow). It is also the fastest to put into action, as the only thing thing needed to make the gun ready to fire is to swipe the thumb safety off as the pistol is drawn.
Magnum carries his .45 "cocked and locked" (condition 1), like any expert would be expected to do, as you can see in this screenshot:
As you can see, the hammer is cocked and the thumb safety is engaged.
However, Magnum's method of carry could be considered dangerous in another way. It is not very secure. He should have a nice inside-the-waistband (IWB) holster (e.g., Milt Sparks Summer Special) along with a proper gun-carry belt (to give proper support to the weight of the gun and holster). With his method of carry (often referred to as "Mexican carry") not being very secure, he could lose the gun while running or tussling with someone, and not have it when he needs it; which would put him in danger.
BTW, his method of carry is highly uncomfortable, especially when sitting down (like in his car). Strong side carry just behind the hip is more comfortable. Most people would consider it faster into action as well.