Independent Vermont Senator and Democratic presidential candidate Bernie Sanders was met with boos from the debate audience when he slammed former New York City Mayor Mike Bloomberg’s support from billionaires, but it was a little unclear at whom the boos were directed: Sanders or the billionaires?

At Tuesday night’s CBS News Democratic Presidential Debate in South Carolina, Bloomberg was one of many candidates to take chunks out of Sanders over his ambitious spending plans, and predicted “If you keep on going, we will elect Bernie. Bernie will lose to Donald Trump,” which would be followed by 20 or 30 years of “catastrophe.”

Sanders demanded time to respond, and lit right into Bloomberg, saying “Mayor Bloomberg has a solid and strong and enthusiastic base of support. The problem is they’re all billionaires.”

That line was met with loud jeers, and one audience member who reacted with what can only be described as anguish. The moment caused Sanders to briefly pause.

While many social media users were confused as to whether the jeers were for Sanders or Bloomberg’s billionaires, there were also many who were convinced it was Sanders being jeered. Judging from the temperature of the room, the latter seems more likely, but you decide.

Watch the clip above via CBS.