The answer to this is a bit on the elusive side. I certainly don't think that John Byro inspired fear in the traditional sense of the word. Part of the reason they returned the horse might have been because Byro's kindness and generous nature helped allow them to make the right decision. Rather than motivating out of fear, Byro's demeanor helped the boys understand the need to return the horse. In this light, the boys begin to understand why there has to be some moral order, some structure, that guides individual actions. The return of the horse demonstrates this. I am sure that there was some level of fear in that both boys understood that taking the horse was not in the pure sense of moral right, but their decision to return it was motivated out of the notion of trying to "do right."
In my opinion.boys were rather conscience stricken, as Honesty of their tribe was at stake. They didn't want to bring bad name to their tribe because of them. When they met the John Byro [owner of the horse who was suffering ] who told them that he would surely have blamed them for stealing his horse but because they belonged to Garoghlanian tribe whose hallmarks are trust and honesty,he must say that this horse is a twin of his horse but not his....this made them realise their mistake and under guilt, their inner voice ordered them to return the horse.
A) It is not proper to judge the boys as exclusively conscious-stricken or afraid. Their decision was motivated by both. They went for their early morning rides for too long a time to brand the decision as conscious-stricken as their conscience would not have permitted them to keep the stolen horse for such a long time. There should be an element of fear in their decision. At the same time, fear is not the only reason. John Byro, who caught them with his horse, handled the situation shrewdly. Instead of blaming the boys of stealing right away, he gave them a chance to redeem themselves. Without claiming the horse as his own expressly, he conveyed to them in no uncertain terms that he had recognised the horse as his own. This saved the boys from the disgrace of admitting their guilt while offering a last chance to return the horse to the rightful owner. The boys were quick to realise that they had almost brought disgrace to their family known for their honesty and integrity. They grabbed the last chance and promptly returned the horse. They knew John would be more expressive if they had not returned the horse!