I watched one of the videos that are out on news sites. I see that some of the previous news reports gave an incorrect impression.
It looks like Harrison wasn't faced with an airliner under his glide path when he started his approach. The route was clear and then the airliner taxied forwards so that only on reasonably short final was he presented with an airliner in front of him.
Thus the airliner taxied in front of an aircraft on approach to land -- although the airliner was in the right place and Harrison wasn't. It doesn't change anything else about what happened that day though.