Our retainers are part of Thancred's secret fraternity and do not really have to combat things to earn the prizes they bring back to players.
However, on a serious note... Until we all are swimming in White Raven Armor Fragments, I don't see where the issue is. The gentleman who got that is just -super- lucky. As is the case with lottery item "minigames", one puts in a token and he may receive a "diamond" or a "lump of coal".
That's the fun part about it. Anything is possible.