312.5 Cabinets, Cutout Boxes, and Meter Socket Enclosures.
Conductors entering enclosures within the scope of this article shall be protected from abrasion and shall comply with 312.5(A) through (C).
(A) Openings to Be Closed. Openings through which conductors enter shall be adequately closed.
(B) Metal Cabinets, Cutout Boxes, and Meter Socket Enclosures. Where metal enclosures within the scope of this article are installed with messenger-supported wiring, open wiring on insulators, or concealed knob-and-tube wiring, conductors shall enter through insulating bushings or, in dry locations, through flexible tubing extending from the last insulating support and firmly secured to the enclosure.
What about this part? The conductors are not "Firmly secured to the enclosure"