Go big or go home! Or, in your case, both.

I think it's an FML because you got caught...I seriously doubt it was an accident.

Lol how do you accidentally add an extra zero especially since if I kbew it was the biggest donation, I would have been very careful not to fuck up. Maybe thats just me

You really should be careful when doing stuff like this. YDI.

Then you said to the donor, "nah, I'm only messing with you, I meant $50000."

How?? Do you use credit card swipes or electronic tablets? You should let the donor fill in the information on the device. And receipt confirm the amount (assuming your org gives physical receipts) before you make it out, it'll give the brain an accuracy boost. These are both things that we do at the nonprofit I work for.

You are an idiot!

Some Zeros are not Heros!