I have gotten two GNGs from my single senor fun pickle.
However, a couple of caveats:
-I didn't actually notice when I got my 2nd GNG, so I guess there is a possibility someone dumped it in my bag. I don't know why anyone would do that though, and I couldn't find a mention of it in my log history.
-I had a little trouble with my pickle the other day. It got stuck in the air and staff had to fiddle with it to get it down...
-I lent my pickle to a friend for a little bit, so when I got it back perhaps I was reset as a new owner.
EDIT: In the name of science, if you happened to anonymously gift me a GNG, please speak up :)