Tried installing Windows 10 on MacBook Pro from a USB...failed
Try to install Windows 10 via an empty DVD by burning the ISO to it through disk utility. I used a DVD-R with 4.7GB of space on it and after the Mac restarts when BCA finishes it should boot into the Windows installer. 

If the problem persists just restart the Mac again and hold Option as soon as it starts and you should see a boot menu it should show either EFI boot or Windows whether your Mac supports EFI boot.