Trying to stop it would’ve meant a bullet to his head. I can only imagine in horror what it must’ve been like to be helpless in his situation IF he was sympathetic and a non Nazi believer.
Trying to be fair requires one to consider the facts of this case in detail.
In general it is my understanding that it was not a bullet to the head for having issues with being a camp guard. I am not sure about this (it has been some years since i read about this)having issues with that duty could ask to be transferred from the Totenkopfbande to a Waffen SS combat unit. As the Waffen SS was big on rough and ready, lacking tactical finesse with resulting high casualties, for a fellow who just wanted to survive the war it was not that nice an alternative
That said, if while a guard he refused an order, he would be disciplined for this, and that might include being executed for refusing to obey an order. The Germans did execute a lot of soldiers for failure to follow orders.
Also It must be remembered that their system was different that the US army: In the US Army you are told you cannot obey an illegal order: how exactly you go about this is left up in the air. In the Germans army you were allowed to question the legality of an order. However, if your commanding officer said “On my authority you are to do this” it meant that the moral responsibility for the action was transferred to him. Hence at that point you had to obey the order, regardless of your personal feeling on it. You may object but this was their legal system. it did allow a lot of folks to go along with crimes though, as they could argue they were simply obeying orders and not morally culpable.
So what is the moral culpability of a 20 year old soldier who was on the outer perimeter of the camp? Well if he was a guard in 1942 he was a volunteer in the SS, drafting did not start until 1943. So he was a volunteer in an organization that was criminal, by the Nuremburg tribunal. He could have gotten out of it by offering to go to the front lines, but such action was very dangerous. A lot of young men who idealistically that join organizations find that it is not such great thing and then just seek to survive, I find that hard to fault.
On the other hand, It seems he knew what was going on. He felt guilt about it. he has lived a long life. It is hard to feel sorry for him if he is somehow punished, even up to death (which will not be imposed).
On the other hand, once again, at this late date it seems a little odd. In the late 1940s significant numbers of high level NAZIs were let go with a slap on the wrist. Guys who were actually at the Wannsee conference and folks who were in the role of defining the policies of the NAZI party. Folks with much more culpability who were in their 30s and 40s at the time served in the west german government into the 1970s. To have let them go with a slap on the wrist or even less, and at this late date go after a 20 year old, who was a minor cog in the system seems.....very hypocritical.
If you are going to do that, then by rights you should also go after all the members of 506 PIR (band of brothers fame) that landed on D-day. That particular regiment was well documented for several cases of executing prisoners in cold blood in Normandy. The details are in the books “Band of Brothers and Currahee!, there really is no doubt about that, they are by their own words implicated. Does anyone think that is right to go these soldiers at this late date?
How about the GPU, NKVD and various Stalinist members who were involved in all the crimes such as the Kaytan forest massacres, show trials of the 1930s? there has never been any punishment. Once again the crimes of the communist part were epic, but a very much doubt a 20 year old kid caught up in one of these organizations has much ability to stop any of their crimes.
Back to the 94 year old guy: Not saying he does not have some guilt. But it would take the wisdom of Solomon to know ho to be fair at this late date. Not that I will shed a tear for him if he is punished, but it might be wiser that this date to leave it to a higher power, as we are told to leave vengeance to the Lord in the good book. Ultimately I hope he is sorry and hopefully get gets forgiveness. If he is not, then he is facing a more severe punishment that any of Human agency is possible of imposing.