The drive failure after cable disconnect from the drive side could be of a simple electro-mechanical nature. The micro-USB3.0 connectors are pretty mechanically weak, especially in shroud/shield mounting area, while the cable overmold is usually very stiff. Moving out the cable might happen in a bending manner, and solder bonds between the connector pins and internal PCB might develop cracks, preventing the USB link from proper detection of Rx termination in one or another link direction. But this kind of failure usually develops over time, and signs of "connection flakiness" should be noticeable before the final failure.
Regarding electricals of disconnect from one or other end of a cable, unfortunately there are differences, but they would more likely cause a trouble with software end on the host, and unlikely kill the HDD.
In general, unplugging a cable (possibly in the middle of essential directory management operation) is called "surprise disconnect". Due to uncountable variety of conditions at the moment of disconnect, USB specifications do not regulate this event, and system protection and recovery is "implementation-specific". In other words, all bets are off with the surprise disconnect.