From the link above "This is because a reverse-bias voltage above 1 to 1.5 V[4][5][6] will destroy the center layer of dielectric material via electrochemical reduction (see redox reactions).
Following the loss of the dielectric material, the capacitor will short circuit, and with sufficient short circuit current, the electrolyte will rapidly heat up and either leak or cause the capacitor to burst, often in a spectacularly dramatic fashion."
Here "short circuit" is relative. For a capacitor autopsy see:
https://www.pa4tim.nl/?p=1385