You don't need to contact Ebay.
Has the buyer opened a case?
If not, do nothing.
The buyer can't win a return case because they have nothing to return.
If they open an 'item not received' case, as long as you have tracking which a) proves delivery and b) was uploaded before a case was opened, you would win the case.
"There are two ways to be fooled. One is to believe what isn't true; the other is to refuse to believe what is true.”
Søren Kierkegaard, Danish philosopher (1813 - 1855)