I would check to make sure the battery terminals are tight. I had a similar issue a couple of months back. I was riding at 55-60mph and my bike cut out,It started right back up while I was still rolling, happened twice after this. I woke up the next morning and noticed that my battery tender hadn't kicked off and was still charging. I had a loose negative terminal, tightened it up and problem solved.

2006 865 Neon Blue/Jet Black Speedmaster,790cams, TTP Stage 2 Firestarter, Epco Exhaust with 10.25" Samson Vrod baffles, UNI pods with 40 pilots, 150 mains,Thruxton needles, 3 turns out.