Levin smokes constantly so I wouldn't take that as much of sign unless you counted him smoking 2x as much.
You would probably have to define what you mean by meltdown. I wouldn't say Stanley crumbled under pressure before the water shot. I am not sure if pressure really affect his shot selection. I have a feeling he just didn't think about the situation enough. After that the pressure may have gotten to him. Levin in the interviews pretty much say the pressure got to him.
I said to my son that the next time the camera pans over to Levin, he is going to be smoking 2 at a time. I needed a cigarette after that and I don't even smoke!