I think the decison to deny the Foden goal was correct -it was offside.
I think the decision not to give Mahrez a penalty was correct as well - it first checked he was/wasnot offside int he build up and didnt use an arm and then checked if it was a foul - it got all of those correct
Calvert Lewin in my opinion could have been sent off - but that is a subjective type decision
Foden was nt a penalty -even he didnt appeal
so out of those 4decisions I think it got 3 definitely correct - the onyl one i would question was the possible red for Calvert Lewin
So yes overall it worked
It has also worked for us in the lastcouple fo games (penalties, retaken penalties)