Olivier,
Please dont take this lying down ! I went thro' the same hell last year with DD in 2nd grade then 7-the exact same cultural baggage that you are referring to. Among other things, DD was strictly told NOT to answer 'a single question' in class. It so killed the spirit of learning in her. She started counting down from day 90 for school to end and hated every day in school. I still carry the guilt but had too many things to battle (a problem pregnancy, a very very demanding job etc.) and so asked DD to treat this an experience on how teachers can be and how she should be mentally strong and not get affected by it (too much to ask of a 7 year old).
The teacher subtly apologized to me when we ran into her a year later but that doesn't reverse what we went thro'.
Please dont take this..I am wiser now. I don't have a specific action plan for you but I am sure your gut feeling and the forum will guide better!
Good luck and pl keep us posted.