[edit] to clarify what may be a point of confusion:

Rich parents are often in a position to comfortably gift their kid(s) tens of thousands of dollars for their first down payment.

Non-rich parents are more often in a position to somewhat-uncomfortably “gift” that money. It’s a gift on paper, but it’s actually a loan and they need the money back eventually (maybe for the next-oldest kid to borrow for the same purpose, lol). That’s when it’s fraud.

“Here are bank records showing the defendant received $5,000 dollars. Here are further records that show payments back to the person who sent the original $5,000. They occur over a span of eleven months. Eight transactions are for $500, one is for $450, and a later one is for $550, totaling $5,000. Only one month in this otherwise contiguous span—December—is skipped, with no payment occurring. Mr. [defendant], was this $5,000 in fact a loan?”

You’d have reasonable doubt?