I believe that an instructor can not only learn from other instructors, but from student as well. When you have done your very best teach someone, listen and watch your student more closely. They can be very creative, even though you may have taught the skill, and the student didn't perform it just like your demonstration, the same result was achieved. (Doctors aren't all the same either). Other classmates can learn as well.
I really like this. We should always remember that we're never finished learning and growing. New knowledge and approaches may be found in many situations.
Comment on Mary Stuart's post:
I agree that people can learn from others in any situation. Sometimes a student will bring up a point that the instructor hasn't considered and it is an opportunity for growth for all!