The only way you can win a case for item not received, is to enter a valid tracking number into the case details showing delivery. Then, the case would close in your favour , no need to refund.
If you ignored the case, and did not enter any tracking to show this delivery , and did not refund within 3 days then the buyer can escalate and eBay step in and force the refund. You may have gained a damaging defect on your account too, if the buyer escalated.
@caprcorn_0