Elbows Bend, Power Ends?

Is an early arm bend during the pull truly incorrect?

Many coaches use the term “elbows bend, power ends.” The thought process behind this theory is that once the athlete bends their arms before finishing the pull, this can decrease the acceleration on the bar. Some times an early bend also causes the lifter to pull themselves to the bar, causing their chest to pull forward, not allowing for a vertical extension. While all these thoughts are valid, I feel like in few cases an early arm can be acceptable. An early arm bend is acceptable is when the athlete bends their arms slightly during the course of the pull and is able to keep both arms bent at the same angle throughout the finish of the pull. Therefor the arms never re-extend at the finish of the pull. If the arms were to re-extend this would a decrease the acceleration on the barbell and thus be incorrect. Also an early arm bend can be acceptable is if the arm bend does not cause the athlete to pull themselves to the barbell, and the athlete is able to stay vertical at the finish of the pull.