If I'm not mistaken the prep cook Tomas mentioned something like ... that if the knife is too sharp it could cut into bone which could then be included with the fish portions/filets. I suspect this would then require extra prep work to remove the bone pieces.
I have experienced this fileting salmon with a sharp Victorinox filet knife... made a poor decision on where to cut and ended up cutting into the backbone versus sliding on top of it.
The prep room I once worked in was not unlike Tomas's work except larger with maybe a dozen prep cooks mostly working on box after box of veggies.
Ripert is very lucky to have Tomas.. it's a tough job physically and mentally.