a couple people told me that there was a deer over in the blanket area of the pit.... it got backed into the corner, freaked out, then jumped over the fence and through the crowd...
but it wasn't during NC, it was much earlier that day...
Same deer...different time.
It happened. Brian has documented numerous testimonials to confirm the deer during Nickel Creek's set.
It was either a mass hallucination, or perhaps Ferg accidentally conjured a deer whilst trying to conjure the moon at Chris Thile's request.