I was taught that the four elements of a self defense technique are:
1) Neutralize the attack
2) Position for advantage
3) Neutralize the attacker
4) Escape
Often, two or three of these are done with the same motion but the concepts are still there. A cover out is the escape. Getting out of range of the crippled attacker is an important part of a self defense technique as it prevents any further hostile action. Covering also returns you to a fighting stance with a guard so that you will be best prepared for another incoming attack.
I cover after every technique and I don't do it for show.