In this Letter, we examine the inconsistencies of the model for the 7-azaindole base-pair phototautomerization presented by Catalán et al. (Proc. Natl. Acad. Sci. (USA) 96 (1999) 8338; Chem. Phys. Lett. 318 (2000) 629) citing up-to-date experiments utilizing modern techniques in molecular science. We also present evidence that rejects the 'theorem' (del Valle et al., Int. J. Quant. Chem. 77 (2000) 118) presented by these authors based on the fortuitous coincidence of the fluorescence bands of the cation and anion in 7-azaindole.