Why can the media say 'Jewish terrorist' but not Arab or 'Palestinian' terrorist?

Last week, a Jew named Jack Teitel was convicted of murdering a 'Palestinian' taxi driver and a 'Palestinian' shepherd, and was sentenced to two consecutive terms of life in prison (not to be shortened by any 'prisoner exchange'). Teitel was referred to as a 'Jewish terrorist' in all of Israel's mainstream media, as well as in such international media as Sky News, the Times of London, the Los