I understand how they work, and I'm pretty sure the voltage in the secondary winding is higher than that
but weird things do happen- in that pic, you can see the lighter discoloured section on the side of the coil pack where an arc has been jumping to the bracket rail that runs along the side of the coil. both the coils (all of them) and the rail end up with carbon marks from that.
I've taped the replacement coils and the bracket rails on both sides to try and increase the resistance to spark-over between them, but it still hasn't completely eliminated the (fairly) occasional misfire
where the heck is the spark energy escaping to?