Wrecked Drawing

So I was working on a graphite drawing today for studio and I went to get it sprayed with fixative after I was done in the spray room. I was initially amazed by how clean the spray room looked and I put my drawing down and did the spraying. While it was drying, I stepped out and went to talk to a few friends in other studios just to see what they are up to. When I got back to the spray room a few minutes after, there were two students in there in front of my drawing...

Him - "Is this your drawing here?"
Me - "Yea..."
Him - "I f*cked up your drawing, I'm really sorry..."
Me - "Uh...(while I take a closer look at my drawing)"
Him - "I'm really sorry, I was opening up a can of paint and this happened."
Her - "I don't know what you are planning to do with it but it's only on the outside, is there a way that you can still use it?"
Him - "Is there anything I can do to make it up?"
Me - "Oh...um...it's okay I guess, I'll post-rationalize something from it...I can be good at that" (trying to crack a joke)
Him - "If there is anything I can do to make it up, let me know...I'm really sorry"
Her - "Get him to buy you a case of beer or something..."
Him - "I sit just outside so let me know"
Me - "Okay..."

I was upset that this unfortunate incident occurred but he stayed at the scene of the crime and waited for my return to apologize, at least he didn't leave, so how can I be mad at one who is willing to admit to his mistakes... It seemed like he felt worse than I did and it seemed like I was comforting him..."It's okay..." kind of thing...