A false dichotomy at best. Terrorism is committing the war crime of targeting civilians to get your way - whether that goal is "freedom" or anything else. The guys in Libya fighting against Gaddaffi's regime? Not terrorists: they were fighting Gaddaffi's military. If they'd hidden and fired missiles into or planted bombs in the middle of Tripoli then they'd have been terrorists - as well as rather less popular, of course, and less likely to be seen as fighting against oppression.
As for 'freedom to determine his own fate', Atta had that from the outset: born in Egypt, studied in Germany then trained in Afghanistan. He could have killed himself any time he wanted, but he wanted to deprive thousands of other people of that right - the very antithesis of a "freedom fighter". Ironically, of course, by bringing about the fall of the Taleban it could be argued he did indirectly bring some freedom to Afghanistan, but I somehow doubt that was his intent!