It shouldn’t be “lump it on the tax payers” or “we can’t do anything, because innocent pension holders may lose out”.
It’s like the bad guy in the movie holding a hostage so they don’t get shot. The haircuts should be extracted from the people responsible: The funds that felt it was appropriate to include asset stripping of public utilities in general pension funds, and the executives they put in place/votes they cast at AGMs to make it happen. If that means that general pension funds fall, the victims should be going after the ones who did it, not the poor bastards having their water bills doubled, or having the cost of bailing out heaped on their government.