The side who had command of the field at the end of the battle would typically have the luxury of looting the battlefield and dealing with the wounded and the dead. The aristocratic dead of one's own side would be prepared for transportation back to their homeland, where they would be buried. The unfortunate dead of the losing side would have to rot on the field until their own servants, retainers, and relatives could sort through the corpses to find their masters or kinsmen. There is no attention given in most medieval sources to the burial of the common soldiery, who would usually not have access to the transportation necessary to cart their dead comrades back home. Looting was an an accepted reality of the medieval battlefield and not in any way contradictory to the norms of the day. Both aristocrats and common soldiers hoped to profit by war, whether from ransoms, looting of towns, or stripping the dead of their arms and valuables. It's best not to think of "chivalry" as a prescriptive thing; there was a wide variance of perspectives on what chivalry was and what it meant both in contemporary usage and among historians today. See /u/thegreenreaper7's post on the historiography of "chivalry" for a look at the complexities of the term. In general, we can say that chivalry was not a binary thing and military actions were not judged on a basis of being "chivalrous" or "unchivalrous." Participating in the culture of chivalry did not prevent medieval aristocrats from being practical warriors on the battlefield.