Storyline Boolean Variables are passed as String instead of Boolean
I had to modify the script to make this work:
var bool = false;
var play = GetPlayer();
bool = (String(play.GetVar("StorylineBooleanVariable"))=="true");
This way, the "StorylineBoolanVariable" (which is Boolean is Storyline) is first parsed as String. Then, it is compared to the string "true".
Hope it helps. There's a download in the link above to see. My two cents: use numbers: 0 and 1 if you can, instead of Booleans. (You can toggle Booleans in Storyline as well using the "Not" in adjust variable trigger. However, you can't do that with multiple variables, only one by one.)