Chinese Obj 122 Broken?

So ive had the miss fortune of running into this thing with a maus using the top shell with 130pen, and failed to do jack to it no matter where i shot, so trying to work out where best for the next time i tried the pen simulator only to find i should be able to pen the front turret checks except doing so does nothing to the tank at all.

shouldnt this be say no pen possible rather then sure shoot here and get killed?