Are you sure it wasn't a static electric shock, rather than AC? If you live in a dry climate, or in a cold climate without a humidifier, and you may have walked across a carpet, it could have been a spark of static electricity. Especially if it hasn't reoccured.
If you buy a similar model from the same manufacturer, you can leave the sink fittings in place. Unplug the power and disconnect the waste pipe. Undo the bayonet fitting securing the waste disposal unit to the sink fitting. Fit new unit to sink fitting, reconnect waste pipe and power. Run the unit with plenty of water to check for leaks. Job done.
TURN OFF POWER before sticking your hand in.!!
But first check the reset button underneath the unit. Also, try to rotate the spinner with hex key usually provided.
Drink beer and then recycle glass bottle or aluminum can
Then research recycling route for all recycled and non-recycled waste products If you need further help, I’m available over the phone at https://www.6ya.com/expert/gene_9f0ef4df2f9897e7
The two drains are connected, but below the disposal. Likely if it's not draining down, you still have a clog, and the person the "cleared" the drain didn't.
Sometimes the disposal rotor is jammed by a piece of chicken bone for example. You can use the supplied hex key to stick into a hole at the bottom and jiggle the rotor free.
Check on the bottom of the unit, the shaft usually goes all the way through and on the bottom has a socket you can put an allen wrench in to twist it. IF that is not the case, you can use a wooden broom handle through the opening in the sink as a lever to break loose any jams