Easy to fix, but if you want everything to be "perfect", it will take a little bit of work.
I'm assuming that when you chopped, you actually busted your buddy out (in the TD), ending the tournament. So:
- Load your tournament
- Undo the bust out of your buddy (press 'S'). This will restart the tournament, since now you and he are back in
- Press CTRL+C to initiate a chop. Configure the chop, press OK and the tournament will end
The only "problem" with this is that your bust-out times and the tournament end time will be skewed (off by a week, based on your description). You can adjust these, if you really care, by using the Adjust Rankings dialog on the Players tab. But I'd only do this if you *really* care, because it's a bit of a pain.