Tech Noir first he didn’t have a bullet in the chamber of his pistol. Why wouldn’t a killing me machine have his weapon ready to kill. Then instead of firing at Sarah he slowly aims the gun up her body (we see the laser dot go up her body) bypassing the heart, neck, spine lots of juicy parts a machine made for killing would of known would kill her. No he waits till it’s on her head just in time for Kyle to save her.
Later he empties a clip from a uzi at her. Of all those bullets only one hit the person that was between her and the terminator. Now using your logic of lots of bullets flying in a relatively small place should hit the target cause the terminator is some master marksman, how did that lady only get hit with one bullet l, and the Sarah got out unscathed.
Those are two examples from one scene. There are loads more.
I’ll tell you how. It’s all due to story, and building tension in the film.
It’s story telling no different than what TZero did.