I can understand Steven K Amos (the host) not getting it out - he has a comdey career to think of and maybe didn't want to have this coming back to haunt him at a later date.
He did seem to be somewhat dimensionally confused though. When inputting his details to the web-based survey he gave length as 9.2 and girth as 4. The survey expected the size in centimetres but he seemed to think inches - it wasn't until later that he realised the mistake. Whether the mistake was genuine or a setup for a later joke wasn't clear.
However, in cm or inches 9.2 x 4 does seems to be disproportionate. A length of 9.2" is impressive but a girth of 4" seems low if measured completely around or excessively high if measured across. If the host of a penis-related documentary can't measure correctly then no wonder there is so much debate about size.
As for the rest of the documentary, it had the usual content for these things - growth techniques / devices, surgery, medical talking heads and the public. The two guys having hypnosis and meeting with the doctor to learn to accept their sizes was novel and maybe the most worthwhile part.
J