  We investigate the joint $\Lambda \bar{\Lambda}$ decay in the reaction $e^+
e^- \rightarrow \gamma \Lambda(\rightarrow p\pi^-) \bar{\Lambda}(\rightarrow
\bar{p}\pi^+)$. This reaction may provide information on the electromagnetic
form factors of the Lambda baryon, in the time-like region. We present a
conventional diagram-based calculation where production and decay steps are
coherent and summations over final-state proton and anti-proton spins are
performed. The resulting cross-section distribution is explictly covariant as
it is expressed in scalar products of the four-momentum vectors of the
participating particles. We compare this calculation with that of the folding
method which we extend and make explicitly covariant. In the folding method
production and decay distributions, not amplitudes, are folded together. Of
particular importance is then a correct counting of the number of possible
intermediate-hyperon-spin states.
