Scottish fans at the T In The Park festival are accusing Eminem of lip-synching his performance.
Gigwise reported that fans were "disgusted" by the lip-synching; Eminem was accused of having his microphone turned off while trying to ad lib.
Fans continue to debate whether he was actually rapping along to the backing track, or whether he was merely miming along to a recording.
Adding mild insult to supposed injury, the revived rap megastar repeatedly referenced Edinburgh, unaware that he was performing in Balado, halfway between Edinburgh and Dundee.
This tour is the first Eminem has done in the UK in five years. He performed a whopping 29-song retrospective of his career, including songs from the chart-dominating Recovery.
In other fan misadventures, the beginning of his performance was delayed by a group of fans with laser pens. Eminem reportedly feared for his safety and required security to find them.
Undercover.com.au