Greetings from Afghanistan!
Your S1 is correct about double tapping, plus the fact that there are two types of military education codes: “Correspondence CRS Total # Hrs” and correspondence/distant learning.
When a resident course code is used, the course name and year completed is listed under Section VI of the ERB. When a correspondence/distant learning course is used, the course name and year will not appear, however the “Correspondence CRS Total # Hrs” will update with the appropriate number of hours. So if your S1 were to use a “resident course code” for a correspondence course, they would be absolutely wrong.
Now I’ll try to explain the double tapping part by way of example.
Soldier completed CLS online and ATRRS transfered the points onto the ERB under “Correspondence CRS Total # Hrs”. Soldier went to S1 and they updated his ERB with CLS using the resident course code. CLS showed up into Section VI and the system automatically awarded more points. Now the Soldier was awarded points twice for the same course.