The only evidence the FDA relied on to show the danger of Four Loko, Joose and other booze-laced energy drinks were studies that examined consumption of “alcohol mixed with energy drink” generally. One study explicitly limited its focus to Red Bull vodkas.

“The most widely cited study in the war on [alcoholic energy drinks]… does not mention pre-mixed [drinks] in any way, making it impossible to distinguish between pre-mixed drinks and the consumption of cocktails – such as vodka and Red Bull or ‘Jaeger Bombs,’ which contain Jagermeister and Red Bull,” says a May 27 study by Baylen Linnekin for the Competitive Enterprise Institute.

In other words, the FDA relied on research on Red Bull vodkas to ban Four Loko while leaving Red Bull vodkas untouched.