Because, by the blow he has taken just right now it would have actually impacted his spinal cord little more than its saturation. He might not feel that pain right now, but it will surely make him admit in hospital for more than week under bedrest.
And, Biyu didn't do this just because of her anger. She actually has a beautiful gift for him!!
Biyu and William heard foot steps approaching them and Biyu smiled nervously, well, she pretended to be nervous.
"Ahh…. that should be my partner. Sorry, uhm…but I need to use the washroom" saying so Biyu escaped. Meanwhile, William sneered.
He would have at least got to touch her hand while she helps him to stand up, however, this so- called partner really ruined up everything.