I have no doubt this can happen, but I seriously doubt that is what happened to my hen, I think it was a freak accident. I spend a lot of time just watching the birds, and have never seen one of the drakes act even remotely interested in the hens. What I do see is the hens perching on the side of the duck pond (it's one of those preformed hard plastic liner ponds) then leaning down into the pond to get a drink. To help minimize splashing I would keep the water about 4 inches below the edge of the pond so the ducks could swim and splash but most of the water stayed in the pond. There were shallow sections at both ends that they used to get out, the chickens and turkeys would occasionally stand in those sections also to cool off. I think she was leaning over to get a drink, and fell into the deeper section. Then was unable to get to a shallow section.
The pond has since been removed and replaced with a kiddy pool. The ducks can't dive but they can still swim around and bathe, and the chickens walk around in it all the time also. No deep areas they can't get out of. At some point I will set up the pond again, but outside of the poultry pen where the chickens are less likely to decide to get a drink, but the ducks can still go for a swim.
