Craig, I did some research and thinking on this the other night. But with the circumstances, I did not want to muddy the waters with any last-minute confusion.
I had always thought the vase was an Aldo Nason design and didn't pay much attention to the Ermanno that was in Pina's book. When I checked on Antique Helper, there was a lamp of the same decor attributed to Ermanno. Ermanno and Aldo are cousins, so it is quite possible that Ermanno executed the design. But even if he executed it, the attribution should go to Aldo. The designer gets the credit and the executor may or may not get mentioned. Your friend mentioned Radi. And true, it does look like something he would design. Now the real confusion comes in. Aldo executed many of Radi's designs at AVeM. Perhaps some of the artists were more talented with certain techniques, so were tasked with the execution.
In the case of this vase, Rago Arts, Antique Helper, and Pina credit Ermanno Nason for AVeM (Pina getting her information from Rago). Rago & Pina have Aldo Nason as the designer. This seems pretty clear until that pesky GF label comes in. When I thought about the label, the scene from Steve Martin's movie The Jerk went through my mind -- the scene where he is leaving and he selects things from the house that he needs. I got this vision of Galliano & Giorgio Ferro doing this when they left AVeM. Giorgio picks up the vase and says, "And we need this..." and they walk out with their vase, chair, and an armload of other things when they left AVeM.
On the serious side -- sometimes the lines between furnaces are hard to draw when it comes to marketing. It may be that GF simply marketed the vase that was made by Ermanno using Aldo's design.
The more I look at Murano glass, the less clear things become. For example, I see often that both Flavio Poli and Archimede Seguso are credited with certain designs. Chances are that the designs were begun in these cases at Seguso VdA and that Archimede continued to make them when he left VdA to start his own company. Who actually did the designs we will probably never know unless someone finds the original drawings somewhere. In the case of your friend's vase, production might have continued when the Ferros left AVeM. I do wish we could find the answer. All I know is that it is a masterful vase and well worth owning. I still lean toward Aldo as the designer, but the mention of Radi did make me look much harder.