Agh, my friend at work is mad at me

Last night I was working late and noticed that two of my data sources didn't match (they're supposed to match). We had already delivered a bunch of stuff to the client, so I literally almost had a heart attack. Two of the labels had been switched around. It was my friend who did it, and while I wasn't upset at him, I had to find out what was right and what was wrong, so I went to the head of the department (the only one in the office at the time). Now my friend is pissed that I went to the head, but I had to know immediately whether we had delivered bad data <img alt="sad.gif" src="http://files.kickrunners.com/smilies/sad.gif">