so how exactly do you "decimate" a person?
decimate = to kill one in every ten of (a group of people, originally a mutinous Roman legion) as a punishment for the whole group
Ah...we have a technical one.
Your stated definition is correct HOWEVER that is only one of many meanings. It also means: to kill, destroy, or remove a large percentage or part of.
Now...wouldn't you agree that he was decimated