I mean, the hanging is a bit much. Even normal people would kinda freak out since this isn't meant to be a horror game/haunted house 😭
So the motive of the murder is that incident of the wine, huh. Maybe the customer was someone who had allergic reaction to it and died? Or there was something very special about the menu they were supposed to serve that day that was super important and messing up the wine caused strong emotional distress to the guest.
I'm not gonna lie, I already suspect the sommelier. Him saying "it's a desecration of wine" sounds over the top. It would've made more sense if he had agreed with the chef about the mariage. Like, you know, if he had said something more like "I picked the wine specifically to go with the food the customer ordered, wrong wine will make the food taste weird, and now you ruined the restaurant's reputation!". Or maybe, "You embarrassed me as the sommelier!" Then it wouldn't come off as weird to me.