Is there an instant win condition by abusing a loophole in Bang?
The cards in question are: Showdown

Showdown - All cards may be played as they were BANG!. BANG! cards may be played as they were Missed!.

The designer notes what the card should read.

Actually, the correct text should be that BANG! card must be played as Missed!, otherwise Suzy Lafayette armed with a Volcanic could shoot the whole deck!

and the cards Volcanic and Suzy Lafayette

Volcanic - (Weapon) Max distance: 1. You may play as many BANG! cards as you wish.
Suzy Lafayette - As soon as she remains with no cards in her hand, she draws a card from the deck.

This response differs from the publisher's answer, or lack there of:

Q: Shootout. There are questions about how this interacts with player abilities: Calamity Janet ... Willy the Kid..... Suzy Lafayette. If she has a Volcanic card during a Shootout, she can keep drawing new cards and using them as Bang!s until she kills all the other players, if she wants. Should there be some way to limit these situations??
A: About your questions: please consider that unpredictability is a BANG! feature and it is part of his style. We want BANG! to be characterized by two sides: strategy (bluff) and luck. Characters in Wild West Show are powerful, and sometimes the interactions between two of them can be &quot;lethal&quot; for the opponents, but we think this &quot;chance component&quot; is what makes this expansion so crazy and exhilarating! Have fun with BANG!