I spent time in Buenos Aires and can attest that people go across to Uruguay, gamble and take back the winnings in US dollars. Also the article said there is just one black market - not true at all, there is a huge underground market for luxury non-Argentian commodities such as Apple computers.
Apparently the biggest concern for the staff working on the casino floor was the Argentinean problem. The would take the biggest credit that they could get (this would create net account liquidity problems for the casino department etc).
I wanted to look up what the deal was and forgot until this article.