Overemployed and TS Reinvestigation

So my cousin stopped being a contractor and went commercial after working with his clearance for a bit. After leaving, he worked four remote jobs at one point but mostly 3. All were full time and FWIW they all were happy with the work he was doing and he was getting bonuses and satisfactory performance reviews, so he was doing his work fine.

When he went back to working for a federal contractor, he had one other job. While full time it was task-based and they didn’t care when he did his work as long as it was done so he would typically work it in the evenings. He did not let either employer know he was involved with the other.

He’s up for reinvestigation (TS/SCI) and wondering how bad things look. What are the chances he might be charged for time card fraud? Or will it just boil down to a denied clearance if things go wrong. He really loves the work he’s doing now on the contractor side and can resign from the other but he knows it’s probably too late. Also does the reinvestigation look at IRS transcripts and do they go further through other means than reported to determine where the income is from? He made about 500k on one of the years overemployed. All his income was from employment and all are US companies. Of course if there is even a remote chance he may be charged for this he would rather just say bye to clearance jobs. He says he is squeaky clean otherwise. Is it time to walk?

Not enough info to really say one way or another. If he’s hiding employments why was that?