That explains why I saw a -0.005 balance on my account, did a manual payment this morning and now I owe $0.60 to the pool

At my current speed, it would roughtly take ~3 hours to get back to zero balance.
Luckily the duration of this double awarding was not very long (~8 hours). As a result, even the most harshly affected (payout requested JUST before it was caught) shouldn't require more than half a day to rebuild their balance.
I'm sure you don't get this nearly often enough.
Thank you for being open with whats going on, your status updates are always welcome and helpful. Thank you for running a very stable pool. Thank you for being an honest operator.
In short, thank you for everything that you do. I know you make good money at it but you deserve it.