There is a big difference between the way Froch got dropped and the way Groves went down.
They were both good punches, but if you look at when Froch was dropped in the first fight his hands were straight down by his side pushing up off the ground and bouncing back to his feet. Once he was back on his feet his hands were up in a position to defend himself.
If you look at the way Groves went down, when he hits the ground its a good 5 seconds before he even begins to respond. His leg is bent over, his arms are flat behind his head not moving. Froch was dazed by a great shot but not out, Groves was in hibernation.
They were both good punches, but if you look at when Froch was dropped in the first fight his hands were straight down by his side pushing up off the ground and bouncing back to his feet. Once he was back on his feet his hands were up in a position to defend himself.
If you look at the way Groves went down, when he hits the ground its a good 5 seconds before he even begins to respond. His leg is bent over, his arms are flat behind his head not moving. Froch was dazed by a great shot but not out, Groves was in hibernation.