It is a set of objective facts. Now there may be disagreement regarding the facts and regarding the objectivity of various sources, but it is the responsibility of historians to do their best to determine the correct set of facts by applying critical thinking to as many original historical sources (plenty of which are available for this period) as possible. This is what students should be taught to do.
Army: Blast in Korean DMZ wounds two South Korean soldiers (Reuters)
from the article: PA adopts textbook, banned in Israel, offering both sides' narratives