Most likely Nozomi let ADV buy streaming rights from them to air the shows. Nozomi, unlike ADV and Funimation, doesn't have a VOD outlet or a streaming website. So they seem to sub license their shows (at least the ones they have streaming/VOD rights to) to companies that do have these set ups.
Think of it like Adult Swim airing Fullmetal Alchemist. Funimation has the rights to that show but allowed AS to buy the rights to air the show on their channel. This is a similar deal, only on a smaller scale.