Perhaps "justfied" isnt the right word but hear me out..
As the journalists were exercising their freedom of speech, so were the terrorists exercising their freedom of expression the way they saw fit.
Sure its extreme to us, but its just to them. who decides what the appropriate repercussions should be?
like hows this different from when kids in school here are bullied constantly til they finally snap and react violently? why dont we say the bullies are exercising their freedom of speech huh?
Again, I dont condone the violence but I kinda understand