OP -
1. You don't mention a bankruptcy in your own case.
2. You don't tell us whether there was an IRS lien (which would not be subject to discharge) in the BK case.
3. We know nothing of the asset status or the reorganization plan in the BK case.
4. We don't know if the BK judge ordered the IRS paid and then had to convert the Ch. 13 to a Ch. 7, because there was no feasible plan.
5. You don't tell us whether the credit card debt had gone to judgment (implied by the garnishment question) in the BK case.
If your situation is exactly the same as your friend's, give us all the information about your case, and the answer may change. For the facts that you posted and the question asked, you were given the correct answer.