Well, I was really only making an argument based on your semantic distinction between "ideal" and "benefit". The real point is whether crimes should be covered up or exposed to the light - regardless of whether the perpetrator is dead or not.
Sam wasn't convicted of a crime. He'd first have to have been charged with a crime and then had the opportunity to defend himself in court. There, in court, Sam would have the right to be defended by a lawyer, and eventually a judgement would be made of guilty or not guilty.
The principle we live by in our society is: Innocent until proven guilty.
You brought up an interesting concept in saying: "Being dead doesn't make you innocent of past crimes." It doesn't necessarily make you innocent or guilty but it does make it awfully difficult to try you in court.
Very hypothetically, suppose there was such a preponderance of legally binding evidence that a judge could declare the deceased Sam Culver guilty of having Jonas committed when he didn't have any good reason to think Sam was a danger to himself to others. I'm no expert in this but I think that's the criteria for being committed: It must be shown that you are a danger to yourself or to others.
Well, then, who bears the guilt for Jonas having died, in addition to Jonas for having killed himself? Is it Sam for starting the process of having him committed, or is it the doctors in charge of the sanitarium for just taking Sam's word for it despite no observable criteria to suggest Jonas needed to be committed?
Maybe the sanitarium would admit Sam for a trial observation, based only on Sam's word, for say a couple days or a week. If at the end of that trial period, if they can't determine that Jonas is a danger to himself or to others, they have to release him. If they keep him anyway, despite any any observable criteria that he needs to be there, Jonas's death is on them!
Jonas killed himself two months into his stay, well after any trial observation would have concluded. Jonas died while he was on their watch. They, the doctors running things at the sanitarium were responsible for his safety and failed Jonas in the worst way.
So even if hypothetically it could be proven that Sam was guilty of a crime, maybe fraud, it was the doctors and possibly other employees of the sanitarium that were to blame for Jonas's death. Their malpractice and/or their negligence resulted in Jonas dying on their watch.
It gets complicated, doesn't it?