Utilizing the perspective of finite mixture modeling, this note considers whether a finding of a plausible one-parameter logistic model could be spurious for a population with substantial unobserved heterogeneity. A theoretically and empirically important setting is discussed involving the mixture of two latent classes, with the less restrictive two-parameter logistic model holding within each of the classes while the more restrictive one-parameter logistic model is plausible overall. A numerical example is presented then of obtaining the one-parameter logistic model as a spurious result in a finite mixture study. Implications for behavioral and social research are discussed in light of these findings.