Mesa in July heat, that staple was probably driven through softened jacket and you got a bad pinch, but one crushed line does not prove staples are wrong every time. A T25 staple shot with a light trigger pull and a proper cable stapler leaves the jacket round most of the time, and I have pulled plenty of stapled runs from 2019 that still sweep clean on a certifier. The real problem is the tool and the hand, not the staple itself, and guys who blame the staple are usually the same ones leaning on the gun. Screw clips take triple the time on a long home run and half of them strip out in drywall anyway, so now you have a clip spinning on a screw and a line flopping around. Inside a wall changes nothing for me, a staple does not care if it is behind drywall or in a crawl, the crush point is the crush point. What actually kills you is no service loop and stapling tight around a bend, that is where the loss shows up at the box.

Plywood shoring saved us too, but we added angled braces next time.