Come out of illusions please. There were reports of stocks of drones and other stuff found in Iraq believed to be left by the fleeing Iranian IRGC goons when Iraqi forces conducted a raid on a suspected origin location of the attacks on that pipeline. I am sure that Saudis at least have the capability to trace back the source of the attack.
However, Israeli support for Houthis (from Somaliland across the Red Sea) cannot be ruled out either (however, probably not in the attack on that Saudi pipeline). In fact, a silent understanding between Iranians and Zionists seems to be certain. Both have not attacked each other for months now. Iranian evils prefer killing Muslims over attacking their sworn enemies (i.e. Zionists). As far the Houthis-KSA fighting is concerned, both sides (i.e. Iranians and Zionists) are busy supporting Houthis. Both seem to have deep pain by the signing of Mecca Defense Accord.