It’s a question because the US does not recognize that the morality of Islam is inverted. Good is bad and bad is good. Therefore, he felt that beheading his co-worker was the right thing to do. Non-Muslims must never “oppress” Muslims by being over them in any way – not even at work. Women cannot be over men – this is humiliating and demands redress. Killing his kafir oppressor guarantees the favor of Allah.