"Can't say I'm truly an expert on bird poop, but as a birder and someone who has researched in colonial nest sites and been covered in it, I never would have guessed that was bird poop by the consistency of it."
Lastly, the experienced staff at Wildcare, a Bay Area animal hospital that rescues and releases hundreds of wild birds each year, is equally doubtful too:
"[The poop] doesn't seem to drop quickly enough, for the quantity. Even if the bird was only a few feet above her head, it should have dropped more quickly, also, it's pretty thick and appears to be all urates–not likely. And she licks right where the first poop landed in her ice cream, it would have tasted awful and I suspect she would have made a face or noticed in some way."
Unless creators of the poop video come forward, we may never know for certain if it was staged or not - though judging from the insight of experts, chances are it's more bull than bird.