There are times where an investigation can lead to an actual exoneration.
Say someone accused you of stealing their car at a certain time and location. Police investigate and find solid proof that you were somewhere else at that date and time. That would be an example of when someone could be deemed innocent and exonerated.
In this case it is practically impossible to fully exonerate Trump of the accusation due to the nature and scope of the alleged crime.
Wrong. There's a reason why courts only return verdicts of Guilty and Not Guilty.
They don't say "Innocent" or "Exonerated". In fact, it's an age old smear tactic used by loser prosecutors when speaking to the press after losing. "Not guilty" isn't the same as "Innocent."
As was highlighted in the hearing, you'll never find one single investigation that declares someone "exonerated". It doesn't exist.
You can be ruled out as a suspect, but that doesn't PROVE INNOCENCE BEYOND A SHADOW OF A DOUBT. In your hypothetical, people have been in two place at once, as has happened in the case of twins. Someone identifies the twin as the thief, but you (the one arrested) actually did it. You then use your twin's alibi, like video of him in another place, as evidence.
So, yeah, exonerating is not part of the judicial system, including investigations. You're either charged, or you're not. Suspects are quick to claim exoneration, but that's not accurate, even for Trump.
Mueller was wrong to ever make the statements about obstruction. That's like the police and DA posting your investigation file online for all to see, even though you were never charged. Just the dirt found in the investigation is enough to cast doubt on your character for most. And you never had a chance to defend against the accusations on court. Not a fair way to run a justice system.