  Recently, it was reported by MacLaughlin et al. in Phys. Rev. B 93, 214421
(2016) that \alpha-YbAl_{0.986}Fe_{0.014}B_4 exhibits an anomalous temperature
dependence in the relaxation rate 1/T_{1} of $\mu$SR, and stressed that such
temperature dependence cannot be understood by the scenario based on the
quantum critical valence transition (QCVT) while this compound exhibits a
series of the non-Fermi liquid behaviors explained by the theory of the QCVT.
In this paper, we point out that the anomalous temperature dependence in
1/T_{1} can be understood semi-quantitatively by assuming that the attraction
of a screening cloud of conduction electrons about the \mu^{+} induces a local
magnetic moment arising from a 4f hole on the Yb ion, giving rise to the Kondo
effect between heavy quasiparticles.
