It's not quite as simple as a step up transformer guys. The primary and secondary are connected together on one leg of each winding. So wiring it backwards won't burn it out, but it can induce flyback voltages into the points or ignition module. (I'm sure a breaker point setup would handle it fine) Whether or not anything was damaged is up for debate. But checking for spark is the best first step instead of analyzing what may have been damaged. If there's spark then no harm done.
I'm not arguing, but asking for clarification...
There are 3 terminals on a coil. 2 primary and 1 secondary.
P1 would be connected to 12V
P2 to the points, or other switching device leading to ground.
S1 is connected to the spark plug
S2 is grounded internally to P2 theoretically
When I think about it, I don't see it working. When I draw the circuit, I don't see it working.
If the grounds are internally connected, the switching of the points doesn't happen
If the 12V is connected to the secondary:
things would get ugly.
Maybe a case ground on the coil, but still not internally connected?
Feel free to roll around laughing
Edit: Actually I did some searching and saw a drawing of an electronic ignition showing an internal connection in the coil so maybe my mental picture works for points only. I also saw a drawing for military a points ignition with the condensors (capacitors) in series, which isn't right.