H-Bridge Gates Stuck On
The only explanation I can think for all the gates being high is that the gate driver has failed. Since all the mosfet gates are high, this opened the path directly to ground, overheating the current sense resistor and causing the resistance to change from 0.1 Ohms to 517 Ohms.

I also noticed that the current sense resistor is rated too low for the load I'm using (a 3W 0.1 ohm resistor is more appropriate).

Upon closer inspection I noticed some layout problems: the main current carrying traces of the H-Bridge are too narrow compared to the layout, and the VDrain should connect directly to the FET, whereas I had it connecting right to the VIN pin on the gate driver.

However, even with these problems I'm uncertain what caused the gate driver to fail. Perhaps ESD, or maybe somehow the layout problems above.

In the datasheet there's a note about limiting the current to VDrain with an 100Ohm resistor, perhaps this is the issue. However, the "typical application" schematic does not show any resistor on this trace, and the EVM module schematic just shows a jumper. Not entirely sure what to make of this.