What is wrong with the man?

W: How’s your exam?
M: I failed again.
W: Why? Did you oversleep again?
M: No, I didn’t.
W: Then, what’s wrong with you?
M: I can’t tell you.
W: Come on. I’m your best friend. You can tell me and I can help you.
M: You know, this time I made full preparations, but John told me that he couldn’t pass the exam since he had to spend all his spare time looking after his mother in the hospital. So I let him copy my answer during the exam. And we were caught by the teacher. Both of us failed.