In September 2007, he was involved in a bar brawl at Star City Casino in Sydney. While attending a wedding with his girlfriend Hallam, he was involved in an altercation with another guest, Ben Benson. Johnson had repeatedly punched Benson before stomping on his head as he lay prone on the floor. The court was told that at the time of the offence Johnson was receiving treatment for depression following the suicide of his long-term partner Lainie Woodlands. Upon leaving the court, Johnson was completely remorseful for his actions, stating, "I am very sorry it all happened, I was a bit of a nincompoop and I'm glad that it's all over. I'm looking forward to moving on". He was given a 12-month good behaviour bond, with Johnson to continue with his counselling, and no conviction was reported.