Molecular cobalt-dmg (dmg = dimethylglyoxime) complexes are an important class of electrocatalysts used heavily in mechanistic model studies of the hydrogen evolution reaction (HER). Schrauzers early isolation of a phosphine-stabilized [H-Co-III(dmgH)(2)P(nBu)(3)] complex has long provided circumstantial support for the plausible intermediacy of Co(III)-H species in HER by cobaloximes in solution. Our investigation of this complex has led to a reassignment of its structure as [Co-II(dmgH)(2)P(nBu)(3)], a complex that contains no hydride ligand and dimerizes to form an unsupported CoCo bond in the solid state. A paramagnetic S = 3/2 impurity that forms during the synthesis of [Co-II(dmgH)(2)P(nBu)(3)] when exposed to adventitious oxygen has also been characterized. This impurity features a H-1 NMR resonance at -5.06 ppm that was recently but erroneously attributed to the hydride resonance of [H-Co-III(dmgH)(2)P(nBu)(3)]. We draw attention to this reassignment because of its relevance to cobaloxime hydrides and HER catalysis and because Schrauzers hydridocobaloxime is often cited as the primary example of a bona fide hydride that can be isolated and characterized on this widely studied HER platform.