This is one of the main points behind my pix at
http://webebananas.com - All the pix labeled (910) are taken from my own plants, and posted according to the name on the plant when I received it. So I know what each of them is supposed top be, but that doesn't solve the problem, in some cases, of whether they were correctly labeled when I received them. Who actually knows for sure that they have a true Williams, or Dwarf Cavendish, or ? Praying Hands is pretty much a no brainer, and a red banana clearly isn't a Cavendish. Ebun Musak was pretty well confirmed when the fruit ripened without much color change (stayed green). So the problem comes in verifying your baseline banana. Also, the more I look at "red" bananas, such as Rose, Dwarf Red, Tall Red, DJR, Kru, etc, their male flowers all look identical to me. So I pretty much know it is a red banana by the flower, but not which one. I expected each one to be more unique.
I have a Gran Nain (so labeled) which grew way too tall. So it clearly wasn't GN, but until I had fruit I had no idea what it might be. Turns out to be a Misi Luki - which wasn't a bad substitute to have.