On November 14 Vallis had been drinking alcohol and smoking synthetic cannabis when he got into an argument with his partner.
Ms Goodlet said her client had a "list" of mental health issues and was "obviously remorseful and upset" about his actions.
"He has been doing really, really well - he has a family which means a lot to him. He's aware he has issues and knows who to talk to to address them," she said. "It's been a huge wake-up call for him."
Judge Cameron expressed concern that if Vallis was not sentenced to supervision he could offend again, but Ms Goodlet said her client did not want such a sentence.
"It would be remiss of the court not to impose supervision - it might be inconvenient for him but this sentence would ensure he gets whatever help he needs," Judge Cameron said.
Vallis was convicted, sentenced to six months' supervision and ordered to complete counselling and treatment as directed.