Answer:
Bob violated the Volunteer Standards of Conduct
Step-by-step explanation:
Publication 4961 of the Internal Revenue System (IRS) establishes the Volunteer Standards of Conduct and Ethics Training on 2019 returns for Volunteer Income Tax Assistance (VITA) and Tax Counseling for the Elderly (TCE) volunteers.
This IRS publication specifically prohibits the following:
"As a volunteer in the VITA/TCE Programs, you must:
... 4. Not knowingly prepare false returns. ..."
Bob knowingly helped a taxpayer to prepare a false report.