@bmarkman I am no expert by any means here; I have had an Ubuntu Nexus 4 for three weeks. But have you tried to just hold the buttons to see if something else happens? I know I did it a few times, but I forgot if I held the buttons till I saw the robot again.
Basically I just did this a couple of times following the steps until I saw big orange circles on my phone flashing like a strobe light (I didn't know that meant the OS was installing).
EDIT #2: Also I'm pretty sure at least once I ignored the installer's instructions and just hit continue. The installer is actually more efficient than they give credit for, but it's not as easy as installing Ubuntu or Zorin to a laptop. It's kind of like 2008-level desktop install, you have to "beat it up" a bit. Just be persistent, because once you get the orange flashing circles it's just waiting for it to show up. But it took me like 5 tries (I actually installed it twice because I didn't know what the circles were. I almost did it three times but while I started to research the circles I saw the Ubuntu Touch loading screen). Good luck! Have confidence with it. It really works well on this phone!