Sadly my beans did not pop. I will take BD clones at appropriate time and size to match other six beans. A hiccup, indeed. But its not the end of the world. I'm funny about planting extra seeds. I hate throwing viable seedlings/teens away. So, I successfully cloned 3 BD they have shown roots through their 1.5 inch rock-wool cubes. I transplanted the three BD clones to one gallon fabric pots.
When I see this mutation, it is often on clones (monster cropped) I cut from plants with flowering hormones active. As others said its not a big deal, and your grow is looking good!