Got negative 15000EUR on paypall account.

Hello. I am new in here but i looking for explanations what could happen.
The situation:
I was sales manager at my ex job (3 weeks are passing since i left) I was selling in ebay, set up business ebay account but added my private paypal. At the starters i was linked my personal bank and debit card (don't have credit card) then after they give me some bank account add to paypal so i deleted my personal banks and card, but left my address.
I sold on ebay at my last week at job item for 15000 EUR when purchase was made and as my last days we withdraw almost all money to bank, we left amount for ebay fees etc.
So The buyer opened case on ebay which i haven't access anymore cause it was business account, I ended up with negative paypal balance (it is on hold), now checked that linked bank account is setting up as ''sepa direct debit mandates''
As I know that ebay cases are now unreal to won as seller and case is opened as item not as described.
My ex boss are trying to give all info to buyer solve the ebay case, but i don't they wont success have been there done that.

What is scenario if my ex job empty bank account which is linked to paypal, what will happen then?
If they lost the case how paypal proceeds this?