Respect with a distance. The more you talked about how incompetent he is, the more he would try to prove himself and then intensify the tension between two of you.
我也遇到过同样的问题,跌跌撞撞碰过犯过不少错误。现在也还做不好,但已经意识到很多时候是我自己没做好。跟中国人更容易起这样的冲突,是因为我们的想法类似,互相明白对方的做法。和老外过招,往往还不明就里呢,就败下阵来了