Troy Polamalu just made a tackle by jumping on a guy, his arms wrapped around the back of the runner but the runner ducked down and Troy's momentum carried him over the top of the runner's head, his arms slipping up and ripping off the helmet off the defender.
....*Then I heard the stupidest comment by the announcer*.......
Whoever it was said something like "I see a lot of these NFL helmets comfing off lately. These players really need to tighten them up more".
If that guy's helmet was tighter, Troy would have ripped his head off with the hemet!!! There's a reason things are made to break-a-way.