Same bug with this GIG (before 1.2)
You must do the GIG directly (when you are near it). If you listen jhonny said that and you leave the area, there is a good chance to have this bug.
Same with another (GIG: Playing for keeps). I read the message on computer and do the GIG without jhonny. After the "Heist", every time i go in little china the game launch his dialogue line
I don't know if there is a solution
For remove this to the screen, you have to active/disable the subtitle option
In my save on 1.2, i do it with jhonny