well, i'm pretty sure he just said he'd mine @ 20% donation rate until the 47 BTC was repayed
If someone stole $1,000 from you and then agree to repay you $0.20 per day would that make it ok?
You will get your money back (minus any interest) in 5,000 or so days. Of course that assumes they don't just stop repayment given they are a criminal.
I mean 20% really? Even if repayment made it ok where does 20% come into the equation. How about 100%? IT IS STOLEN MONEY. On what planet is a thief given the option to extend "repayment" of stolen funds by 500%? and then people should be happy about it?
"Oh thank you Mr. thief for repaying at 20% donation not 10% or 1%."