Global health programs are compelled to demonstrate impact on their target populations. We study an example of social franchising - a popular healthcare delivery model in low/middle-income countries - in the Ugandan private maternal health sector. The discrepancies between the program's official profile and its actual operation reveal the franchise responded to its beneficiaries, but in a way incoherent with typical evidence production on social franchises, which privileges simple narratives blurring the details of program enactment. Building on concepts of not-knowing and the production of success, we consider the implications of an imperative to maintain ambiguity in global health programming and academia.