Before presenting the award for Top Rap Song of the Year at Sunday’s Billboard Music Awards, Kid Rock took it upon himself to call out lip-synching performers.

“Let’s give it up for people lip-synching under pre-recorded music,” he said wryly.

Kid’s comment instantly set Twitter abuzz with speculation. It’s still unclear whether the diss was directed at R&B artist Chris Brown, who had just performed, teen star Selena Gomez, who appeared earlier in the show, or perhaps rap music in general, as Kid prepared to hand over the award to winners Macklemore & Ryan Lewis for their hit “Thrift Shop“.

Whatever his motive, Kid Rock certainly managed to raise a few eyebrows and even received a cheering response from the show’s audience.

Surprisingly, it wasn’t the most uncomfortable part of the show; Justin Bieber was greeted by booing as he accepted the first ever Milestone Award, which is meant to honor musical ingenuity and innovation.  Watch the 57 seconds of awkwardness at billboard.com.