it could be mistake of seller to list at both marketplaces at sametime with same reserve.
so now seller will be going with highest sale point which is flippa i guess. and he can loose account of namejet for this mistake. but just because of losing account in namejet he will not lose big amount....
when we submit listing in namejet there is noway to close it and when he listed in namejet at same time the domain sold in flippa ... so its clearly seller mistake as he listed at both places in same range and same time