Maybe so, but "computer science"
is not the same thing as "training for an IT
job". I belong to an apparently now-crusty generation that doesn't think a university education should exactly coincide with what employers want to hire this year. It's more about building up a solid foundation.
Back to the main topic: at this stage, it looks a lot like he-said/she-said. Whether the expulsion was justified hinges a lot on just how strongly he was told "don't do that any more" and also on the fact of whether it was a test system or on production servers.