So why exactly did Seagal retire?
So when Seagal's character leaves the DEA, he says that it's because his partner was killed and that he's discovered that he's become the very thing he was fighting against. What does he mean by this? Well after this he confesses to a priest that he killed a woman, but doesn't mention the men he killed.
I don't see the problem here. He has no qualms killing evil men in self defense but one stripper who tried to kill him and his partner, that's suddenly drawing the line. It just seems like a cheap excuse for him to go all vigilante later in the film.