  In this paper, we investigate the intrinsic bias in detecting caustic
crossings between Galactic halo and self-lensing events in the Magellanic
Clouds. For this, we determine the region for optimal caustic-crossing
detection in the parameter space of the physical binary separations, $\ell$,
and the total binary lens mass, $M$, and find that the optimal regions for both
populations of events are similar to each other. In particular, if the Galactic
halo is composed of lenses with the claimed average mass of $<M>\sim 0.5
M_\odot$, the optimal binary separation range of Galactic halo events of $3.5
AU\lesssim \ell\lesssim 14 AU$ matches well with that of a Magellanic Cloud
self-lensing event caused by a binary lens with a total mass $M\sim 1 M_\odot$;
well within the mass range of the most probable lens population of stars in the
Magellanic Clouds. Therefore, our computation implies that if the binary
fractions and the distributions of binary separations of the two populations of
lenses are not significantly different from each other, there is no strong
detection bias against Galactic halo caustic-crossing events.
