Is a co-painting done by default?

With me, because of a small dent in the wheel run, the side part was painted (BMW M4 silverstone, fixed price 1000€).The paintr said at collection that he would not have realized with the costs and he would have offered me that too cheap (offer was from other colleagues) Unfortunately, under certain lighting conditions a color difference to the door is recognizable. In order to compensate this, now again side part complete and door had to be painted, which I should now pay with approx. 800€ again fully. How do the professionals, should not have had to paint it from the beginning, or should I draw attention to the facts? Thank you for relevant notes Greeting Dirk