You can download previous versions if you hand-craft download links similar to the current one. For example: download link for x86 7.1beta6 Extra packages is
I tried with 7.1beta1 and it shows the same problem, recognized as lte, i can’t download the 7.0 cd install with the same trick (maybe the notation is different)
Edit: I tried with 7.0beta5 and the bug is not present (the device is recognized as ethernet)