Just before the prestigious show was set to start, fire marshalls decided to get 60 seats from the designer's venue, leaving many people with front row tickets without anywhere to sit.
So Zac's PR agency, HL Group, had to accommodate the guests - which included president of French publishing house Jalou Marie-Jose Susskind-Jalou and her two daughters, L'Officiel stylist Vanessa Bellugeon and Jalouse stylist Jennifer Eymere.
According to WWD, Marie-Jose didn't have a seat and HL Group co-founder Lynn Tesoro tried to find one for her, but was unsuccessful.
So the family decided to leave the venue but vented their frustration at Lynn and the debacle culminated in Jennifer slapping the PR across the face.
Jennifer said: ''I said: 'Don't speak to my mum like this. You have to stop speaking to her like that.' I said: 'Be careful, I am going to slap you,' and she kept doing it, and it just happened. I am sorry, I know it's bad to do that. It was a small slap. It was not strong. I didn't hurt her - it was just to humiliate her. She humiliated my mum, and I humiliated her in front of her crew. VoilÃ . I just said at the end: 'Now you know you don't f**k with French people.'''