I have worked Michalis on this fix and want to testify to the correctness of everything described here. I think this is a great example of exercising: 

1. Using the fellowship to propose a relatively quick fix to the onchain logic, minimizing damage
2. Using onchain governance to refund any harm done to end users. 

Of course, if the amount at risk was substantially larger, this would have possibly been a controversial proposal, but for 120 DOTs, I think it is perfectly fine to allow the network to refund the affected users. 

For accounting purposes, I wish it would have been possible to attach a remark to the proposal, such that, for example, when an affected user sees this unknown transfer from treasury into their account 2 years from now, they have a way to know why it happened. For larger amounts, this is also useful for tax and accounting purposes.

I have worked Michalis on this fix and want to testify to the correctness of everything described here. I think this is a great example of exercising: 

1. Using the fellowship to propose a relatively quick fix to the onchain logic, minimizing damage
2. Using onchain governance to refund any harm done to end users.