Bethesda did not develope NV. I don't know how many times this has to be repeated.
Any game with Bethesda on it is a mess of bugs. Who cares who is the soul developer. You think when cars are made that we look at who the designer team was? Or do we look at the manufacture?
The point is, it has that name on the box, you bet it will be plagued with bugs. Regardless of there "experience" or longevity of creating the same open world games with a different scenery.
Just making a point, not bashing Skyrim or FONV it is just a record of previous titles with that name on it, it is known to be a buggy mess on release day and sometimes for several weeks.
I am not sure either, but I think there were more than one person working on Skyrim that did work on New Vegas or past Fallout games? I know there was Morrowind team members. Am I right?