I believe you.. he just hides it well. Looking at the choke hole it doesn't look very thick it all. I've blown bubbles too thin before and they look like that.
There is something else to consider. Blown glass like that will vary from pipe to pipe regardless of the manufacturer. Admittedly the kip of the choke in the picture you chose to post does look on the thin side. But when compared to my Dagga pipes it protrudes more and, again, the outer lip does look thinner. Mine are different. There is not as much of a protrusion and the lip is definitely thicker. Since glass like this is not mass produced to exacting standard it would be an injudicious assumption to make that all, or most, other pipes made by Dagga would be the same as the one in the picture. Not one of mine has a thinnish looking lip like the one pictured. If anything they are amazingly thick.
While this pictures is not a side angle and does not show the same thing as the picture you posted it does show how the amount of protrusion varies from pipe to pipe.
I have never worked with glass but in my experience with glass pipes it appears to me that the more the glass is stretched/pulled (or whatever) the thinner it gets. I think you would agree to that. Based on my pipes, on the pipes of friends who have bought Dagga pipes on my recommendation and the size of the protrusion of those above, I tend to believe that the one you used a picture of is not truly representative of what would be more normal from a Dagga pipe.
