Violation of Time Reversal Invariance inK0Decays

A $T$-odd correlation observed in the decay $K_L\to {\pi }^{+}{\pi }^{-}{e}^{+}{e}^{-}$ has been cited as direct evidence of time-reversal violation (TRV). Here it is argued that when $\mathrm{CP}$ violation is due to $K^0\overline{K^0}$ mixing it is doubtful that any decay experiment by itself can provide direct evidence for TRV.