No, he was not shown to be in the wrong. And yes, what happens to him spurs Sam's actions afterwards.
Spencer's Cap run and SE were fantastic. A lot of kneejerk reactions kept it from being better appreciated at the moment but it will continue to be re-discovered, now that it can be read in full without readers freaking out that it's going to "ruin" Captain America and all the other nonsense that some fanboys were bleating about at the time.
The criticisms against it were always hollow. Mostly they came from fans who think they can write trying to suggest the "better" version of the story. Of course their suggestions as to how Cap and SE "should" be written were almost always were based on a complete misreading of the story itself. If you go back and read the Cap and SE threads that were active at the time the books were coming out, I know there was at least one poster who kept slamming it on the basis that they were interpreting it as a story about mind control and how Cap should be able to snap out of it and this character should do such and such a thing to wake him up and Steve or Sam should do this or that and always insisting that, you know, there's no way that Cap isn't being ruined forever by this but, of course, Spencer wasn't telling a story about mind control at all, he hadn't ruined Cap in the least, and none of these suggestions had any relevance to where the actual story was going.
I think there's a group of fans who just aren't equipped to deal with long term serialized storytelling and can't stand to be held in suspense for a lengthy period of time. They try to anticipate where the story's going, do it badly, make all kinds of erroneous assumptions, and then take it out on the story itself. And even when it's over and all their hand-wringing has proved to be for nothing, instead of learning the lesson of "well, I really should let a story play out all the way before losing my mind," they just stay angry about it and go on to do the same thing with some other arc.
But I'm glad Spencer's Cap is a storyline that people came come to from a different vantage point now, away from the heated discussions and reactions that may have colored it at the time, and really appreciate what he was doing.