Windows 7: USB boot install 14 Oct

I installed clean via USB flash this morning, Win 7 Ultimate.

Expanding files was stuck at 0% for a few minutes. So, I unplugged a single USB device and install proceeded. All readers take note of this SF learned 'fix'.

That is when I noticed that my DVD drive was spinning. I had neglected to remove the DVD after copying it to the thumb. I ejected the drive and the install interrupted.

Even though I specifically selected to boot from the thumb (via F8), I was indeed installing from the DVD. I did not recv the standard 'Press Any Key To Boot From CD/DVD'.

I am not willing to perform any tests on this at this time. A new clean install is likely in my near future as I continue to test VMs and other apps. But, I am curious. I will assume that I did not deviate from the process described above. I was neither tired nor stoned. I specifically selected to boot from the thumb.

Did Windows install see the DVD and make a jump from the thumb to the ODD?

It would not surprise me. Not long ago I was having a similar problem trying to install XP64 from my hard disk. Even though the setup files were already on the drive, it kept asking for the installation CD. It seemed to be hard coded into Windows setup to look for the CD for absolutely no valid reason.