How would the Otter know the flowers were behind it all?

He was just a florist who sold the flowers but that's his job to sell flowers. He wouldn't have known what they were being used for or by whom? The sniper didn't even seem to know who his victims were. He was just told to shoot random people apparently but why bother? If each person didn't know the operational details they wouldn't be able to finger the ones involved anyway. Also the otter kept muttering that it was the flowers over and over but why would he do that if he was just shot thru the open window? He'd have no idea he'd been shot with the pollen from that flower. But then I guess they wouldn't have had much of a plot for the movie either if Judy couldn't have gotten that big clue to start her on her mission.