Indeed, this could occur, whether it is all white, or just 'splattered'.
Have you ever had a bird fly over and take a crap and it, sadly, landed on your plants?
I know this sounds unlikely, but I keep finding bird feces splattered EVERYWHERE in my backyard and one about 2 feet from my Sarracenia, and I only have a few on my porch!
Has anyone had their plants literally crapped on so they were white? What was the damage? I'm sure somebody has!