Followup by Berger: https://arstechnica.com/science/2020/05/heres-why-nasas-chief-of-human-spaceflight-resigned-and-why-it-matters/ https://arstechnica.com/scie

Followup by Berger: https://arstechnica.com/science/2020/05/heres-why-nasas-chief-of-human-spaceflight-resigned-and-why-it-matters/ https://arstechnica.com/science/2020/05/heres-why-nasas-chie... He guesses that Loverro violated rules around procurement, potentially by pushing Boeing to improve their proposal because he favored a SLS based solution.