No idea, but I’d guess that he did see some combat but probably not the heavy, sustained stuff that you often see in ‘nam movies. By ‘69 the war was on it’s last legs. Nixon was pulling out troops. American troops were being pulled back from the border where most of the action was. Having said that he was deployed in the area around My Lai where US troops were busy not winning hearts and minds, so there was probably no shortage of locals who wanted to take shots at him. As any trooper in Iraq will tell you it is pretty stressful when the enemy is hidden in the civilian population.