Nothing in the article really suggests it actually was the Shabak. In fighting isn't uncommon among Arab militant groups etc. Plus Hezbollah are involved in the conflict within Syria which would make it a target for other groups.
Plus the Shabak's remit is only usually within Israel and the Palestinian territories.
I thought that the usual Israeli tactic was to use really obvious kit, then simply deny all accusations, whilst making dark threats.
There's currently an alphabet soup of Sunni brigades who all have a big hate on for HA, and the combat indicators all point in their direction.
Ah, what a world we live in where the maddest fundamentalists of Islam are fighting the most fervent opponents of Israel over who is the most religious!
The beardymen are doing Mossads work for them. Why should the Israelis spend a shekel on a car full of ANFO when they just have to wait for someone local to build one for themselves?