Google Search results appear to be coming up in our Google Analytics as Referrals. I've tested using a Realtime report, and it's definitely proper search results, not traffic from a different Google Property.
When testing it, I tended to find that my initial click through from a Google search would be considered a referral, but returning and subsequently clicking through again could be an organic Session. However, I only did this a handful of times; it could be that there is no pattern.
There don't seem to be any strange Filters in place or anything.
Has anybody ever encountered this before?
I have done a bit more digging, and noticed that the tracking implementation uses the urchinTracker(), which probably means it's not been updated in about 10 years. Not quite case closed, but it's a likely suspect.