Very certain. i was ACTIVELY searching for him and i didn't see him, while the producer DID introduce him, shiba still had the same dialogue. perhaps it was a fluke,
He's in shopping mall the first time you go there. And is always there until 16th January. If you go to shopping mall (before 16th January) and don't find the scene in shopping mall, that means you already get the scene.
I have checked the code multiple times, and the thing you mentioned shouldn't happen.