If you one hit kill a Z-Pigman, all of the Z-Pigman don't react to the killing sequence

What i was doing was:
1.making a minecraft map
2. do /give @p minecraft:diamond 1 0 {ench:[

{id:16,lvl:10000}

]}
3. All of them reacts to me and try to kill me

What i get instead was
1.making a minecraft map
2. do /give @p minecraft:diamond 1 0 {ench:[

{id:16,lvl:10000}

]}
3. They was like: . . .