If you knew about the leak and didn't report (or can't prove that you reported it) then you could be responsible for any ensuing damage.
There's no way to predict how this will turn out. You'll just have to wait and see.
Just learn a healthy lesson from this. Wherever you rent and you find a negative condition report it to the landlord right away IN WRITING and keep dated photos of the condition and a copy of the notice in your permanent files.
In fact, the day you move into any rental, photograph every inch of the place.
After you move out, it's way to late to claim this, that, and the other thing when the landlord sends you the bill and keeps your deposit.

