Current sense problem

Maybe I can't see the forest for the trees...

I want to use the bridge circuit from UHU HP in another servo(modified Elm-Chan).
Looking for two days at UHU schematic it seems to me it can work correctly only if it NEVER
hits the current limit during positive level of PWM signal applied on pin 3 (CLOCK) of U6A(CD4013).
I'am thinking to insert a XOR gate as frequency doubler (or two diodes )between PWM line and pin 3 of U6A to get true cycle by cycle current limit.

Is this correct ?