The fact is that the pause between "finest" and "families" is there because the Sultan was not happy with his chest of gold items and moved on to see the car, so disappointing Donovan who had expected a much different reaction (what was at stake there is that the Sultan could have not agreed to let them pass into his territory).
However it does leave space for doubt. Furthermore, his lips are unfortunately covered in that moment, due to the Sultan passing in front of him. So, who knows.

About the Hindemburg...

In the comments to this article: http://www.thingsinmovies.com/the-hindenburg-in-indiana-jones-and-the-last-crusade/ one stated

I saw this when it first came out and remember expecting it to be the Hindenburg and then being surprised that it wasn’t. Though I bet it was supposed to be at one point in the creative process.

The ominous music when the Zeppelin is shown can be easily explained by the fact that people associate that type of transportation with disaster, regardless of the specific model of blimp.

EDIT: I've asked these question on an Indiana Jones forum and the ones that do have memories of those moments from 1989 did say that they clearly remember these elements not being there, no "jews" line, no "Hindenburg" name. If it can be of any further evidence, the Zeppelin model used for the film still exists and it has no more details than the ones we see in the film, no Hindenburg stencil.
I think the rumor of an alternate Last Crusade can be easily classified as a legend.