I don't think Cindy is saying it doesn't change behavior, just that typically when it does, the dude had a penchant for acting that way before the joose - like taking a subtle, livable version of a negative behavior and cranking it up x1000.
She's saying it amplifies behaviors, not creates them.
I think that's what she's saying anyways.
That's probably true to an extent but that's mostly something said by addicts that don't want to admit the juice is causing problems that probably wouldn't be there otherwise.