Did he say YOU were going to injure your biceps?
If youre asking these types of questions it's unlikely you'll ever get to the point where youre lifting heavy enough weight to injure anything.
Theres no debate that if someone is going to injure their biceps during rows it's when their hands are supinated.
Just be careful. Knowing the potential hazards of certain lifts is the only way to prevent injury, in most cases.