You ask, "What possible benefit could he [Haniyeh] derive from approving these terrible events?" Good question. On the other hand, if he did not approve them and that responsibility for at least the shooting of the electric worker was claimed by Haniyeh, then the only other explanation is that no one is able to exert any control over the Palestinians. So are they capable of self-government?
Hillary Clinton to call for lifting Cuba embargo (Reuters)
from the article: Egypt says would-be Hamas suicide bomber arrested near Israeli border