Complex sentence: A pivotal issue in the case that the finds were all closely packed which was indicative of burial, although it was not realised that this could have been because the hoard was cast aside in a bag that had since decayed.
Split into simpler sentences: A pivotal issue in the case were that the finds were all closely packed which was indicative of burial. Although it was not realised that this could have been because the hoard was cast aside in a bag that had since decayed.