labor - Overtime at Carrefour

When you hear about suppliers of foreign companies, or even foreign companies themselves, ignoring the labor law and problems with overtime, you think of far away textile factories and shoe producers in the southern parts of China.
It can come closer. Today I was at one of the Carrefour stores in Shanghai and we saw one of the staff members having great trouble in keep on standing on his feet. We inquired and he told us that he started every morning at 10 in the morning till 9:30 in the evening, with one hour lunch break. He worked six days per week, so that would be 63 hours per week.
How could Carrefour get away with such obvious illegal behavior, we wondered loudly. Very simple, we were explained. This guy was not employed by Carrefour itself but by a supplier. So, legally, there was nothing we could blame Carrefour for.
What a relief. Still not smart to exploit such a large amount of people who deal directly with the customers: they might get upset about that.