keeping the leps in with the gar is bad advice coming from somewhere as nearly any good LFS will explain that leps are highly (and often randomly) aggressive with tankmates...going after fins and eyes most of the time. i had one in a comm tank that had to be removed within a little over 24 hours (watched it closely, so luckily only aggression and no casualties). at 9" the gator may have barely realized what was happening to it in time as the leps are quite fast.
unfortunate, but also calls for the need for further research on tankmates before putting a combo together. i would get rid of or move the leps before adding any other fishes--
--solomon