When Gebru presented her demand letter and resignation threat James Dean probably thought she had no leverage and moved quickly against her. That was an extremely poor calculation.
Minor nitpick but I think he's called 'Jeff Dean', one of the co-author of the map-reduce paper. It will be interesting to see whether Google CEO is ready to sacrifice the 'nerd faction' in favor of the 'intersectional faction' of Google, or if he is ready to take the heat.