Sux man...but on the bright side, it's not a difficult job. Do the following When you go to reinstall everything.
1) Get #1 @ TDC,
2) Install the pump/dizzy drive in the correct orientation
3) Clamp the drive in place from the dizzy side with a pair of vice grips
4) Re-install your oil pump (I like to use a thin coat of Hylomar on the gasket and flanges)
5) Remove the vice grips
6) Re-install dizzy
7) Have a beer cuz you are done!
If you have to remove the oil pump again, remove the dizzy and clamp the drive in place first so you don't have to worry about it falling out.
Cheers,
Ross