I'm loving a book currently called 'Transforming the Difficult Child' by Howard Glasser, 2008 edition. There is also a workbook to go with it.
It might sound odd to 'make a rule about over reacting,' but in this context were you are giving a ton and a half of praise for every bit of 'non-over reacting' your child does, I think it makes sense.
Will you child over-react to your calling him on it when he breaks the rule about 'no over-reacting?' Sure he will. But my hunch is that he will get the hang rather quickly that there is more 'fabulous' out of life when he puts his attention on 'what's right' than on 'what's wrong.'
Let me know how it goes, ok?
Grinity