My opinion is that the situation is complicated by the dubious nature of evidence, especially in cases this old. What's more bringing up The Holocaust tends to have a lot of people toss common sense out the window no matter the nature of the accusation. This guy having been cleared by Isreal pretty much says all that needs to be said as far as I'm concerned.
Speaking for myself I think this is mostly a German show trial. To be honest Germany is in an awkward place right now because it tries to make a big show out of being extremely sorry and anti-nazi, while on the other hand there are some disturbing undercurrents coming from that country constantly that play havoc with those claims. Right now, there remains a huge number of people who take a "germany is faking" attitude, or believe that there is a core of extremists left in their power structure that simply know how to play the denial game... watch one hand, while the other is doing something else. Dragging out this guy, and then executing him for Nazi war crimes probably being a way they think they can prove how much they have changed.... when really this is just murder for political gain, as again, if there was much to tie this guy to war crimes, the Isrealis probably would have nailed him to a wall the last time it was brought up. That's my thoughts at any rate.
I'll also be honest in saying that a lot of attitudes against camp guards tend to disgust me in general. Every time I see a show like "Doctor Who" making some huge statement how "Just following orders" is not an excuse, usually makes me very angry. See, it's easy to criticize someone for following orders when you have distance from it. In reality when your within an organization like that and NOT following orders means you being horribly punished or killed, your not given a lot of choice. It's easy to say what someone in that situation SHOULD do from a distance, or to think you would have acted differant when your not actually in that guy's shoes. This doesn't excuse ALL behavior by nazi camp guards, as some of them probably were gleefully sadistic monsters, but at the same time I think a lot of them were probably guys who just weren't heroes. It's one thing to lionize a hero, and have deep respect for someone who steps up at great personal risk or danger, or who sacrifices themselves for a point, it's quite another to look down on someone for NOT being a hero though. I think there is a middle ground here between a guy being a hero standing against the regime, and being some kind of murderous monster.
I say this because I have ill will against any group to the point where I'd support a death camp. Truthfully at my very worst, my attitude is that such excesses are pointless, since if your going to kill them, just embrace a "take no prisoners" attitude on the battlefield (and it would go well off subject for me to explain the differances for those that don't get it). To put things into perspective if I was serving my country, and agreeing with most of what they were doing, but not this, the odds of me choosing to get myself killed and have my family punished to make some symbolic point would be minimal. If I was given an oppertunity to do something to influance policy, or stop the camps, without getting myself or my loved ones killed, I'd probably take it, but I'm not going to tell my commanding officer "No" and then get myself put against a wall and shot, while the goverment starts eyeballing my family to see if they are also "treasonous". This by definition just makes me a human being, I'm not a hero, but I'm not a supervillain either. For most people the oppertunity to make a differance without subjecting themselves to certain death in situations like this does not often present itself. Besides, after they shoot me, the guy they bring in over my cooling corpse to replace me is going to look at MY body and go do the job anyway, so you know... it's not like even my symbolic point is going to spark any kind of flames. Mostly it's just going to make people go "Sh@t I don't want to be him". Basically I feel you have no right to judge someone for following orders in part of an organization like this with those kinds of risks.
I'll also say that while they were the bad guys, there is a differance between someone being a German patriot and getting caught up in the furor to better himself and his country, and someone who was a war criminal. Killing for your country, and even going about the ugly business of war, does not mean someone should be considered a war criminal. Once it's over it's time to chill out. One side's heroes are the other side's war criminals, and which winds up being which depends entirely on the winner. A favorite example (which has nothing to do with camps) is:
http://en.wikipedia.org/wiki/Bomber_Harris
"Bomber" Harris, or "Butcher" Harris as he was known to the germans, was a British war hero who was knighted for his heroism. His big thing was that he was one of the guys who turned around and proceeded to bomb the living bejeezus out of German cities irregardless of collateral damage. "Area Bombing" basiscally meaning "kill as many civilians as possible to break the Germans will to fight", which is pretty much fighting a serious war with the intent of winning. War Sucks because of things like this.
As we, the heroic allies, won the war, we proceed to scream about how Germans were monsterous mass murderers because of what they did during "The Blitz" when we did the same thing, for the same basic reasons, when we were in a position to. You say some camp guard was a mass murderer who "contributed to the deaths of tens of thousands" but what about Harris here, he's a mass murderer, he killed defenseless civilians, and he's a hero, the Brits knighted the guy for this. The differance being that our side won the war so we get to decide who the heroes were.
I'm an extreme realist when it comes to war, which is pretty rare, especially for a militant I think. I'm pretty much of the attitude that when it's over, it's over, and when the surrender has taken place, hunting down people from the other side for fighting in a war, which is a nasty thing, is a bit excessive. It's only really appropriate if you figure that they represent a continued threat, and really when it comes to guys like camp guards, who were doing what was a pretty horrible and shitty job to begin with, hunting them down in most cases is mostly pointless. I think people need to remember that when it's over, it's over, and that if things had gone the other way, the same arguements could be made. A guy like Bomber Harris is no threat without his plane really, and if he isn't involved in trying to continue the war, there is no reason to just let him go home. The same arguement can be made about a lot (but of course not all) of these people being brought up for war crimes during a decades old war. The fact that this guy is 91 years old and hasn't really done anything since the war ended is pretty much a sign that even if everything said about him while he was in the military and a war was on was true, there is no reason to kill him now that it's done with.
I know many people will disagree with me, and I probably haven't expressed my thoughts perfectly, but this is what I think. I hardly have any love for the Nazis, and The Holocaust was terrible, but this seems to be nothing but a show murder for the sake of politics... and like for the third time, The Jews are the vengeful ones (with good reasons) and if they didn't feel this guy needed to have wrongs avenged on him, where the heck does the German goverment get off. Under duress or not, the guy was acting in service to them, even under another regime. They can deny it all they want, but even after losing a war they should respect people who served their country, even if the people in charge then, are differant from those in charge now.