Repairing blown highlights

I photographed this hippo on the Zambezi River in Zimbabwe in sunset lighting. On the illuminated side of the animal, the wet skin reflected the sun's light and detail was lost in some areas. In other words, the highlights were completely blown out. This was unavoidable simply because water reflects the brilliant light from the sun with almost the same intensity as the sun itself. I used the highlight slider in ACR in an attempt to recover the lost detail, but it didn't work. When detail and texture are lost due to overexposure, it can't be brought back with a slider. The only way to address this issue was to clone from skin surrounding the blown-out areas with a lowered opacity. In that way, color and texture replaces the solid white areas but the repaired area still looks like a highlight. My settings were 1/640, f/6.3, 500 ISO, and I used a Canon 500mm f/4 telephoto handheld while on a boat.