Yea, like I said, it only takes one bad run.
I only got 18 free connucopias myself with only two runs left before the event ends, so I imagine I wouldn't get the tank either (but I brought some bags with cores because I wanted the drumsticks for other things so I'm good now). I really don't think even one person will get that tank without spending cores (although the possibility of someone being that insanely lucky does exist. It's just really really puny from what I can tell)