Not necessarily. I have been shooting single action revolvers for over 50 years and have fired thousands and thousands of rounds through them. The hammer drops only when you squeeze the trigger, unless it's a custom hair trigger, touching the trigger won't make the hammer drop.
I was imprecise in my language. I meant he had enough pressure on it to inadvertently slip fire it.
Take one of your SAA revolvers, hold the trigger down, and you’ll see the hammer won’t lock back.