It's true that Israel tried to instigate a diplomatic crisis between America and Egypt, and for that purpose the Israeli intelligence used Israeli spies and a spy cell of Egyptian Jews to set off small bombs, in fact firebombs, at select targets- like a post office, an American library, and movie theaters. The few bombs that did actually blew off only caused modest property damage. Eventually the spy cell was caught by the Egyptians and two of them were executed, the rest tutored and imprisoned until they were released in a pow exchanged following the six day war.
What can be said is this was a very stupid and amateurish operation and as it turned out to be such a colossal failure the Israeli leaders behind this operation tried to pin the blame on each other and clear themselves. The prime minister and the Army's Chief of stuff claimed they didn't know about the operation. Lavon, who was the defense minister claimed he didn't give the order to carry out the plan, and that the Army's chief of intelligence operated on his own (which he of course denies).