In the second half of 2020 there have been two heavily discussed challenges to arbitration awards stemming from an arbitrator’s nondisclosure. The more recent, OOGC America, L.L.C. v. Chesapeake Exploration, L.L.C, was an appeal in the U.S. Fifth Circuit. The other, Eiser Infrastructure Limited and Energia Solar Luxemburg S.À.R.L. v. Kingdom of Spain, was heard…