Have we wronged the buyer of the stolen phone by giving him half of what he paid to the thief, and how do we restore his right if we cannot reach him?

The majority of jurists are of the opinion that whoever buys stolen goods must return them to their owner for free, and then the buyer can claim back from the seller what he paid. However, some scholars, such as Ishaq ibn Rahawayh, and they attributed this ruling to the Rightly Guided Caliphs, hold that if the buyer is not accused of theft, then the one from whom the goods were stolen must return the full price to the buyer, and then he (the owner) can claim from the thief. This is based on a hadith narrated by Al-Nasa'i from Usaid ibn Hudair. So, if the father believes that the buyer is not accused, and he wishes to clear his conscience, then that is better.