The rapper pocketed the item and continued with his set
The song is lifted from the rapper's 2014 album 'Forest Hills Drive'
'All we wanna do is be free'
J Cole, Knife Party, B.o.B and Foxes also set for July event
The rapper says is is sorry for the "highly offensive" lyrics
The pair reportedly plan a musical collaboration during a night out in London
They join Rihanna, Jessie J, Calvin Harris on the bill on July 8