Employment Law Questions? Ask an Employment Lawyer.
I see that you've posted this question to me now twice. I left it open for others to consider, but no one responded. The issue is that your question is simply not specific enough. What do you want to know? It seems you want to be advised on how to avoid any sort of investigation stress or getting fired.
I'm afraid that there is no reasonable way to make sure of that. Evening paying back the entirety of the funds that you considered to be a gray area would not legally stop them from investigating what they may believe to be a criminal act or civil wrong to them.