you have a lot of input delay online, also the delay of the hd television if u have one, the time you need to see and react to a move online is the same input delay on the execution of a move which will make the move you are trying to punish looks safe if you are used to the online timing.
thats why the controversy of kung lao hat, raiden teleport reptile dash sonya dive kick etc, even i didnt know why i couldnt even d1 a kung lao spin when i was first visiting VSM and going to tournaments, their hd television had like 4 or 5 frames of input delay, thanks god they made the game mode on some hd ones, and the monitors move almost perfect, kung lao down hat wasnt overpower but the input delay made it look like that, so sad nrs nerfed that move and ruined that character