I believe the first jury saw the officers as following department guidelines and standard operating procedures, and therefore not guilty. They were just doing what the LAPD had trained them to do, and therefore nothing wrong.
However if it takes a tasering, 6 kicks, and 50+ blows from 4+ officers on a scene before they are able to handcuff a suspect, then something is wrong with the handcuffing technique.
How many blows are necessary when the suspect continually lunges as officers as King did multiple times? Have you seen the entire video?