The JET tool wasn't working for my device for some reason. It detected the phone, and tried to switch modes but it seemed like my PC wasn't executing the code fast enough.
The manual method with emmc_recover worked perfect. Now hboot downgraded.
Jet isn't perfect. It was originally developed for Jewel, which is a single carrier (sprint) version of the one x. While it also works on the various qualcomm based one x/xl phones, there appear to be timing issues between the slightly different one x/xl hardware. Coupled with the different speeds of people's computers and the buggy nature of the linux usb 3.0 driver's backward compatibility, it introduces a timing complexity that isn't easy to handle in a single solution. That is why the manual method sometimes works when Jet does not.
-SLS-