Does off mean off?

In our Jayco Greyhawk Class C motorhome, Jayco wired the battery disconnect so that everything is off when the battery is disconnected, except the converter. I learned that the hard way when I replaced the converter. I hit the battery disconnect switch thinking that would suffice. Needless to say, I had a nice shower of sparks when both negative and positive wires hit the converter chassis while putting the new converter in place of the old one. Not sure if it should be like that or not, but I left it that way.

-Michael