Hello Mike, all,
Ultimately, I consider suttas to be the authority. And AN6.63 does say that "Contact is the cause by which kamma comes into play".
Sometimes I strongly disagree with what modern authors claim that the Buddha has said.
"Life is a struggle. Life will throw curveballs at you, it will humble you, it will attempt to break you down. And just when you think things are starting to look up, life will smack you back down with ruthless indifference..."