The man you are talking about is the man with the blowtorch to Martha whom batman murdered. And all the incriminating evidence Bruce gathered on Lex was illegally obtained which makes in inadmissible in court and subjects anyone who handled it to very serious Criminal charges.
I could be wrong, but I didn't see Batman murder that guy. I thought he hurt him but not with a fatal wound.
Yes, there may be sand from the desert on lois' notebook. It's well known Lois was in the desert, it's natural there would be sand on her notebook, none of that proves anything. The prosecution has no murder weapon, they have no suspect, and they have no access to the crime scene, and they have no jurisdiction to get access to any of those things.
Yet, the movie tells us that it was proven. How plausible would it be to a jury that Lois' notebook could have been taken from her and shot at by someone using rare bullets that few could have gotten their hands on? I believe General Swanwick further strengthened Lois' case. Ultimately, though, the movie still establishes that the investigation bore fruit. It was proven. So Lois was successful, according to the script, and, consequently, she was not useless. Especially in the court of public opinion, in which it can be argued Superman needed to be vindicated most, linking Lex (who was already taken in for his other crimes) with the incident in Africa exonerates Superman for that particular event in the eyes of the people. She helped Superman in that respect, just like she helped him in the final conflicts with Batman and Doomsday.
And the General states his knowledge of the situation was classified and there was nothing presented in the film to imply any of that was changing.
There was nothing in the film to imply that it hadn't changed either. What we do know, though, is that Lois said she had proved her suspicions. We can only conclude, then, that she had gathered enough evidence to make a compelling case, if not to a jury but to the public who needed to have their faith in Superman restored.
If the film featured a story arc for Lois where she legitimately and thoroughly investigates the conflict and gathers enough admissible and irrefutable evidence against Lex, yes that would of been an awesome character arc which would of been way better than her falling off things and drowning and playing Superman's constant damsel in distress.
Legitimately? What was illegitimate about her investigation? As for the rest, the film tells us that she did get that kind of evidence against Lex. I'm all for show more than tell, so that would have been better, but just because we didn't see it doesn't mean it didn't happen. Lois was more than a damsel in this movie. She saved Superman as much as he saved her. First, according to the film, she saved him in the court of public opinion by exculpating him from his alleged involvement in the incident in Africa. She also helped prevent Batman from going in for the kill. Finally, she helped Superman out of the water from which he had retrieved the kryptonite spear (which she alone knew the location). Don't get me wrong, I would have liked fewer rescues, but they don't negate Lois' other contributions and her other strengths.