Denzel realized early on that it wasn't about a robbery "This ain't no robbery!" and in the end figured out that the whole thing was a scheme to bring light to a bigger crime. Clive Owen was more vigilante than mere criminal and even did Denzel a solid by giving him one of the diamonds to give to his girl (I believe they had a discussion about it earlier in the film).

I saw it more as a "You deserve this" than a "Fuck you I outsmarted you"