I think the main consideration will be whether it's cheaper to find "everyone innocent" or "everyone guilty". With the former they run the risk of a potentially exorbitant lawsuit settlement with Juventus (if the board has any dignity whatsoever they'll seek damages), as well as the "egg on their faces" for blundering the first judgement, damaging the league's credibility in this regard. For the latter, they risk Inter not taking this lying down (as we did four years ago), having FIFA and UEFA intervene while attempting to strongarm a decision (again, as they did in our case, threatening to exclude Italian teams from their competitions unless a definitive verdict was handed out) and just creating a mess in general. Also, the further denigration of Serie A being seen as "corrupt and unsportsmanlike".
Tough call.