What is the difference between a "Self-Radicalized" terrorist, and one that has been "Radicalized" by some other means?

It seems that every time we hear of a radical Islamist terrorist killing or attempting to kill people, the press and the government want to try to make a distinction between self-radicalized, or not self-radicalized.
To quote the former Secretary of State, Hillary Clinton “What difference does it make?”
I think it is political obfuscation, but I could be wrong.
Hence the question.