Really, really weird that the article doesn't even mention nitrogen, nostoc or heterocysts. I'm not sure you can have a conversation about the great oxygen holocaust without at least bringing up one of the primary reasons we know "something" about the conditions before the event, specifically that there are still bacteria around today who are putting out a pretty significant amount of effort to create anoxygenic environments specifically for nitrogen fixation; that nitrogen as a terminal electron receptor basically 'cant happen' in the presence of oxygen.

Its just weird to not discuss the evolutionary lineage that still uses pre-oxygenation event hardware (with some extreme bug fixes to deal with oxygen) to fix nitrogen.