Although, to be honest, not at all surprised by the actions of ChipMixer in this case. They have a pretty solid reputation for being fair and helpful. Excellent result for all concerned it would seem?
So the problem here is a problem during the operation of ChipMixer, right? And a lucky guy got some free money

Obviously, ChipMixer's solution is really cool, but will it happen in the future? I don't know much about this technique, but how does this error occur?
Well in cases such as this one where a service will be losing money I know they'll try to prevent it from happening in the future since scandals and accusations loke this are bad for their reputation. Simply no user wants to have a problem when it comes to mixing their crypto or not to have any problem at all when it comes to delays.