Series resistor? 10.8V? Your coil is in parallel with a back-to-back diode/zener pair with no series resistor.
Your LED is in parallel with the coil which is charged to give nearly 5V across your coil and across your LED/330ohm combination and discharged to dump the coil energy and give you concerns about LED reverse bias. The activity is all relative to your 5V rail, not ground.
If you see 3V across the 330 ohm resistor in series with the LED, this is the forward biased conducting side of your situation, not the discharge of the coil where the LED reverse bias would happen. When reverse biased, the resistor voltage should be nearly zero (0 relative or the same voltage as your 5V rail).