Towards the end of the tour, a major incident occurred during their first concert at the Oakland Coliseum on 23 July 1977. Upon arrival at the stadium, it was alleged that Bindon pushed a member of promoter Bill Graham's stage crew out of the way as the band entered the stadium via a backstage ramp. Tension had been simmering between Graham's staff and Led Zeppelin's security team during the day, and as Grant and Bindon were walking down the ramp near the end of the concert, words were exchanged with stage crew chief Jim Downey, which resulted in Bindon knocking Downey unconscious.