I think if you read the article closely, there was a point in the 1990s when Zizek had access to actual political influence. During that period, he was an anti-communist and called for NATO bombing of his country. His stripes revealed.
Zizek is a pragmatist in his leftism. If pulling the lever results in future where people can have a role in their government, it sucks that we find ourselves in a trolley problem, but that’s reality. Most leftists don’t even have a seat at the table or the ear of one who does, so I don’t find him responsible for having a leftist agenda when advising folks with the willingness and capacity to pull the lever. Even the ones pulling the lever didn’t themselves drop the bombs. The diffusion of responsibility absolves the soldier who sees no moral quandary, but not the philosopher who does? If anything, Zizek is honest about his reasoning, and focusing on outcomes. You can blame him for arguing for any outcome that resulted in violence or loss of life or limb, and I think he wouldn’t reject that being laid at his feet. However, he wasn’t the one slouching towards Bethlehem. He’s perhaps complicit like Lando Calrissian was, but Lando fought for the rebels all the same.