While investigating bug 1049175 I discovered that too many modules are being unloaded, including libata, cdrom, isofs which results in the driver disk iso showing up multiple times.
You can observe this in the output of journalctl by searching for driver-update, it will reload the drivers and the iso will show up as a new device which will then be processed.
Verified with anaconda-19.31.70-1.el7, RHEL-7.0-20140320.0. Only isofs module is being unloaded now. Moving to verified.
This request was resolved in Red Hat Enterprise Linux 7.0.
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