Hand design change

[jspick]

I have noticed that the hands of the newer smiths that I have are different than the older ones in several ways.
But my question is on the leading edge of the hand there is a bump on it so when you pull the trigger single action the hand disengages or pushes off the star notch that it is indexed on when it is fired.
Why do they make the hands this way now? It seems that it would be detrimental to have the gun to function this way.

Thanks, John