This is exactly something that would happen in my classroom:
My students started reading Going Where I'm Coming From in my class today, and we have just enough copies for a class set. In fact, in my largest class, if everyone shows up, I have to lend out my teacher copy, which is all marked up with teacher goodness.
Of course, in the very first class today, one of my student had a nose bleed and dripped blood over a few of the pages.
We were all sufficiently grossed out. I wiped the pages down with Clorox wipes, and later in the day after the pages dried, the stain didn't obviously look like blood.
But we still know...