I think the point of that whole rescue scene was

1. To shock the viewer out of their preconceived notions of Matt Dillon's character. He was a bigot, but at the same time he was capable of putting his life onthe line to save another person's. That's a little more complexity than we usually get from our movies, and even in real life something like that is tough to compute. This scene made it difficult to box Dillion in as a 'good' guy or 'bad' guy

2. To show us that no matter what, Dillon could NOT be redeemed for his bigotry. The key to this scene is to watch the woman's reaction *after* the rescue. As she is being escorted away from the scene of the accident, she looks back at Dillon with just as much contempt as she ever had for him. At the same time she's probably greatful to be alive, but you can see on her face that his sins of the past have not and will not be stricken for the record.

So no, I don't think it was a redemption scene, and no I don't think it should have been removed.