Before you do that ask Driftwood how many documented or even undocumented cases there are of accidents with a '66 because of it being fired out of battery.
Well, I was present at a match where a '73 that had had its safety lever removed had an out of battery discharge. The lever slammed forward with enough force that it broke. Yes, it broke. Left the shooter with a very sore hand.
No, I cannot site case and location of any others, but over the years there have been several reported on the SASS wire. More with '73s that have had their safeties removed. And I disagree with you Mako about a lot of competitors disabling the lever safety on their '73s. Used to be a lot did. In part it was because the spring Uberti puts on the lever is too strong, causing the shooter to have to squeeze the lever closed with more force than should be necessary. But there are now several after market springs available for the lever safety that make the lever safety much more user friendly. Most shooters I know are now replacing the spring and leaving the lever safety in place. It is part of the standard action job done by many smiths.
Yes, there have also been documented incidents of out or battery discharges from the shooter attempting to force a round into the chamber. Several years ago there was even a video of this happening on the SASS wire. And another video demonstrating how it could happen. Slamming the lever to force a recalcitrant round into the chamber generated enough momentum with the firing pin to allow it to fly forward and fire the primer in a round that had not yet been fully chambered. This was sometimes further exacerbated by shooters who had lightened the firing pin return spring, allowing the firing pin to jump forward with more energy than if the spring had not been lightened. Yes, we all know we should never force a round into the chamber, but that is exactly what was happening.
What nobody has yet mentioned is that with all the toggle link rifles, the Henry, The '66, and the '73, they never lock up in the solid way that a more modern design does. With a toggle link rifle, the links only hold the bolt in place against recoil when they are lined up completely straight, or when they have gone slightly over center. But if the lever is not completely closed, the links are not quite lined up straight yet. They still have a slight bit of angle to them. If the cartridge should fire when the links are still not quite lined up, there is nothing preventing the bolt from flying back from the force of recoil. Nothing except the the shooter's hand in the loop of the lever. It is pretty much the same thing as if somebody snuck up behind you while you are standing and shoved your knees forward. Your legs will collapse and you will fall like a ton of bricks.
To make matters worse, until very recently, the only thing fastening the firing pin extension to the bolt was a thin pin about .062 in diameter. And there have been instances where an out of battery discharge has sent the bolt backwards with enough force that the pin sheared. Then the firing pin extension has exited the frame heading towards the shooter's face. In the instances I have read about the hammer deflected the firing pin extension so that at least it did not hit the shooter in the eye, but it did strike their cheek. No, I cannot site place, name and date, but this HAS happened. More recently Uberti has changed the method of attachment of the firing pin extension to the bolt, exactly because of this concern. But there are still plenty of older rifles out there with the thin pin holding the firing pin extension in place.
As far as all of us being perfect shooters and never allowing our finger to graze the trigger while we work the lever, I know that I am not perfect, and I suspect that many shooters who think they are perfect may in fact not be. I have sure seen plenty of fingers on triggers while the lever was being worked.
The '92 mechanism employs two locking lugs that rise up and physically block the bolt from moving backwards. The timing of the mechanism is such that the lugs have already begun to slide into their mating slots on the bolt before the bolt is all the way home. That is one reason why the '92 is an inherently stronger action than the toggle links. But it is also why Winchester never felt the need to incorporate a lever safety on the '92 like they did with the '73. Despite the fact that both rifles were chambered for the exact same cartridges.
The lever safety is the main reason why I chose a '73 over a '66 when I bought my first toggle link gun. Also because I don't care for yellow guns, but that is a purely aesthetic decision. Plus, it only takes the removal of one screw to remove the side plates of the '73 for cleaning, with a '66 you also have to take out the lever screw and the lever.
And I really like the dustcover on a '73. Makes for an inexpensive way to personalize the rifle.