Rabbi Yudel Shain on the design of the rotating pen

Shmarya published Rabbi Yudel Shain description of a proper shechita procedure. In our earlier email exchanges with Rabbi Yudel Shain he wrote:

"Due to the metal head restrainer design, the Shoichet is afraid that his "chalef" (ritual knife) will hit the metal frame and nick his "chalef" he does not go deep and the v'iridin (veins) aren't severed."

This makes a lot of sense as the Shochtim might be afraid to do a "free flowing" cut because of the proximity of the restraining metal (the bracket holding the head). This also might be the reason why the Shochtim are hesitant with the cut, the veins are not properly severed and the cows on occasion are still wondering around after the shechita.

If we forget for a moment the argument about the proper restraining devise the real question might be, if the rotating pen in use at Agriprocessors plant is simply poorly designed?