You are certainly entitled to your opinion. :) I personally feel that there are a lot more liabilities associated with revolvers as opposed to automatics although I know this isn't the general consensus. Since I could use a distraction I will explain more specifically my reasons for feeling this way....
A while back I scanned the internet to find all the documented cases of accidental firearm discharges and then categorize them according to the reason. The two primary reasons I found were: 1) discharge while trying to de-cock due to slipped finger on a gun with hammer, 2) on an automatic, failing to remove the magazine before emptying the chamber, followed by pulling the trigger for takedown.
So I do think that de-cocking a revolver is a major liability.
Here's a more specific example. Let's say your girlfriend is walking to her car in the parking garage when she is jumped by a thug. She pulls her revolver and screams at him to get back
while cocking it. He runs away, and then she, still stricken with panic, points the gun down at her feet and attempts to
de-cock the revolver which requires performing a very specific sequence of actions in an exact order. In her panic her thumb slips and the hammer strikes, accidentally firing a round which strikes the metal I-beam 2 feet away, bounces back and hits her.
In a slight variation, lets say after
cocking the revolver the thug doesn't run away but instead smacks the gun out of her hand, it falls on the exposed hammer which causes the revolver to discharge a round in some random direction.
Because the hammer is exposed its also subject to problems while being
stuffed away in her purse filled with lint, dirt, little pieces of paper, chewing gum etc. All of this can get in-between the exposed hammer and could cause a failure to fire when it is needed most.
Now on the issue of dangerous gasses, you say this never happens but it does happen.
Look at this picture and see how simple it is to lose your own thumb simply due to holding the gun imperfectly. I can easily see someone making the mistake of holding the gun this way under a stressful situation, especially a female who is carrying a gun for SD purposes without having spent tons of time training with it and becoming totally familiar with it.
Now in all fairness, it is also possible to hurt oneself by gripping an automatic poorly as well. I will admit that I was once shooting my G26 using the
straight-thumbs/IPSC grip, and I was trying to grip it as high up as I could to get a low bore axis, and the bottom edge of the slide (which has a sawtooth pattern from the slide grip) kept grazing the top edge of my right hand. I didn't notice until I had emptied the magazine and saw the blood. Still, this was only a very minor injury, not at all comparable to having one's thumb blown off entirely.
Another liability associated with a revolver is due to the double action nature.
Perhaps she decided to keep 1 round of the revolver empty so that she could "rest easy." Then one night she is a little scared and she decided to adjust the rotation to line up a shot, but she forgets that the first action of the trigger is to rotate the cylinder. Later that night she is approached by a thug he pushes himself onto her, she quickly grabs her revolver out of her purse and points it in his face and pulls the trigger; click, no boom. She is surprised and confused that it didn't go off, and the thug seizes this opportunity to grab the gun out of her hands before she has time to pull the trigger again.
From a mechanical perspective, a revolver does have a very
simple action but that doesn't necessarily mean it's the more reliable than the complex action of an automatic. I can think of a way for this very simple action to become dangerous, all it takes is for the cylinder rotation to be SLIGHTLY off when the hammer falls and then the bullet nose can become lodged in the barrel. Revolver rounds are often loaded quite hot, and most revolvers have an inherently small amount of metal connecting the frame to the barrel. As a result the lodged bullet can cause the entire barrel to explode and break off the gun. I've seen several pictures of this having occurred for the exact scenario I just described.
I don't shoot revolvers much but I also
suspect it is somehow possible that the nose of the bullet could snag on the barrel causing it to be aligned not quite right so the hammer doesnt hit the primer properly and doesnt ignite it, and if this is true then its not always the case that "You could just pull the trigger the second time" because the cylinder is now jammed.
Cheers!