"Turning back" couldn't have been the decision that caused their predicament. They'd not have any reason to turn back in the first iteration of the incident that lead to the loops. They'd be plowing ahead just like they always do. So Riker was being overly cautious and not particularly insightful with his comment.
I don't get this.
As you said, the first time through they had no reason to turn back, so that means that going forwards is what gets them into trouble. So how is Riker being "overly cautious and not particularly insightful" when he suggests doing something that will take the Enterprise away from the event that causes the incident?