How do you figure that? The article you linked does not seem to say that at all:
If there was an Israeli strike in Gaza before June 28th, I'm not aware of it.
It's discussed in the article from the Israel Times, the one you dismissed. The IDF launched an air strike to assassinate someone, and the rockets fired by Hamas were a few hours later.
Israel Times said:At least 16 rockets were fired at Israel Monday morning, most of them hitting open areas in the Eshkol region, the army said.
The security sources, who spoke on condition of anonymity, assessed that Hamas had probably launched the barrage in revenge for an Israeli airstrike several hours earlier which killed one person and injured three more.
A member of Hamas’s militant wing was killed in the attack, Gaza health official Ashraf al-Kidra said.
While Israel has maintained it holds Hamas responsible for all rocket attacks, officials have said that smaller groups, such as Islamic Jihad, are usually behind the rocket attacks, while Hamas squads generally attempt to thwart the rocket fire.
Hamas hasn’t fired rockets into Israel since Operation Pillar of Defense ended in November 2012,...
If Hamas was serious about preventing rockets they wouldn't mind Israel pounding the competing groups when they launch.