I killed a muchmore esc doing that.

The strangest part is it died a couple days later, after some racing right in the middle of a practice run. Landed a jump and the car just lost all power and rolled into the pipe. It just partially failed and took a few days of running on turf to fully die.

I'd say if it still works you're 90% still ok. But there might be issues later, but only time will tell. Best thing to do is shorten the wires so it can't be plugged in backwards next time. Maybe put some red heat shrink on pos and red paint (fingernail polish might work well if the ladies have it) on the battery.