Yes, the respondent is correct.
Don't put a comma after the main clause when a dependent (subordinate) clause follows it (except for cases of extreme contrast).
1. She was late for class because her alarm clock was broken.
2. The cat scratched at the door while I was eating.
3. She was still quite upset by the criticism of her acting, even though she had just won the Oscar. (correct: extreme contrast)
2. Use commas after introductory a) clauses, b) phrases, or c) words that come before the main clause.
If you have any questions, contact the registrar.
Common starter words for introductory clauses that should be followed by a comma include after, although, as, because, if, since, when, while.
While I was eating, the cat scratched at the door.
Because her alarm clock was broken, she was late for class.
If you are ill, you ought to see a doctor.
When the snow stops falling, we'll shovel the driveway.
(Courtesy, Purdue Uni.)