Benn's thesis that absent an investigation the government will corrode is flawed. Because the government, and the governing system has been corroded for a long time, this 'affair' could , and did take place. Israeli governments, successively have been rife with intrigues, back-stabbing, and therefore with flawed decision-making processes.
U.S., allies conduct 20 air strikes in Syria and Iraq against ISIS, says U.S. military (Reuters)
from the article: Yes, investigate