He may want to check with his union. However, being financially vulnerable IS going to raise some red flags. Whether he can be FIRED will depend on whether his employment requires solvency. While not a direct threat to his job, there might be a nexus to his actions that can be terms as "irresponsible" and thus render his judgment and suitability for continued employment question.
He needs to consult his union rep and a union attorney for answers.
- Carl