Some years ago, a very close friend of mine, a guy called Ephraim Lewis, was tasered by LA cops, he fell backwards off a balcony and died from massive head injuries. Bad things happen to real people...
That's one of the reasons I'm not fond of TASERs either. That and the possibility of tasering someone with a heart problem. By and large though they inflict less serious injuries than impact weapons. In most cases they cause no injury at all (other than the intended temporary incapacitation) Had the LA cops engaged your friend physically the end result might well have been the same. We'll never know and it's tragic either way.