The inquiry, led by SpaceX with assistance from government and industry experts, is still looking into the cause of the breach, which may be only a symptom and not the root of the Sept. 1 mishap.
That doesn't mean that the root cause is sabotage nor does it mean it isn't. It just means that root cause analysis has not been completed.
The root cause isn't known but the fact that they can trace it to a failure of the helium containment system nearly rules out sabotage as a contributing factor.
Why do you suggest that rules out sabotage? What better way to cause a rocket to explode than to rupture a high pressure tank inside the oxidizer tank right after it was fueled.
https://spaceflightnow.com/2016/09/23/falcon-9-rocket-explos...
So yes it's something they considered but there wasn't any actual sabotage - it was just a tangent in the investigation.