Karmello Anthony self defense question.

In Texas or other states that apply. This has been bugging me but I’m not a lawyer so I have no clue. Would it mean it would be ok to shoot someone I see pushing/touching someone else I felt was “potentially life threatening” If he had been found to be not guilty due to self defense? Would that set precedence for similar situations where someone subjectively sees a person touch or a push and then could shoot the person doing the touching/pushing? If I’m not mistaken self defense isn’t just a first person application?