Consistent kinetic description of degenerate electron exchange (ion-molecular charge transfer) reaction in the liquid phase based on the encounter theory has been performed. This has made it possible to allow for re-encounters of reactants and the attendant additional dephasing of electron spin during the encounter. The applicability range of the approximation of noncorrelated spectral migration that is commonly used to describe spectroscopic manifestation of degenerate electron exchange in strong magnetic fields has been refined. It is shown that for radicals with large hyperfine interaction constants the discrepancy between the results obtained, and the approximation of noncorrelated frequency migration may be considerable.