Abandons Harediism and has to pay a fine for dictionaries he doesn’t have?

A friend of mine, a man of high standing, got into a problem. I talked to him and realized the magnitude of the blessing.
He was one of the most successful young men in the yeshiva where he studied [in his sub-sector, it is the best yeshiva], achieved significant achievements, and a respected Torah figure took him as a son-in-law for his daughter. Of course, he also gave him an apartment worth several million today, in terms of value and value.
Everything went smoothly, just like in the stories of the Torah scholar who constantly studied in the kollel and was truly considered a significant Torah figure.
One day, Hada began to feel that he was searching for the truth, and to his understanding, it was not in Haredi but in other places. His wife was also quite in the same direction, and so he, his wife, and their children cautiously began taking decisive steps out of Haredi, in his opinion, toward the truth and the service of God.
He is persecuted, despised, and humiliated by his father-in-law and his wife’s entire family in a shocking and offensive manner, something on a truly inhuman scale. And they do not spare their daughter or grandchildren, certainly not his crimes, and of course they have long ago erased the obligation to honor the Torah towards the 18th son-in-law in their home. [The rest are just mediocre people with a huge mouth and not much intelligence…]
I shared his grief, and told him something that I thought was both advice and perhaps a charge.
Give your father-in-law back the expensive apartment, and its value. [He is also in debt because of the apartment he gave you, he is eating away at your heart, give him back and maybe some of the hostility and resentment will subside]
I heard this advice from a famous yeshiva head who, even though his grandchildren are now getting married, still carries debts from the marriages of his sons and daughters. In recent years, he himself has been whispering in a high-pitched tone that Harediism is not the proper way to serve God, and anyone who comes to him for advice about problems in Harediism, the first thing he says is, “Give back the apartment, what you took is theft.”
My friend heard what I said that he would return the apartment and claims not to for several reasons, some clearly stated, some did not know how to articulate it, and I will make you open your mouth to the mute.

1. His father-in-law will be hurt by the return of the money.
2. I have nowhere to scrape up such huge sums of money.
3. What he took in the law was that his parents did not fulfill their obligation to teach him art, and the apartment was a place to teach him art. His father-in-law wanted exactly the type of person who did not fulfill their obligation to teach him art. He wanted it, he got it, and he paid for it.
4. They never pledged to remain ultra-Orthodox.
5. For years he did provide the goods. A child in a crowded place lived in financial poverty [today he claims also in intellectual poverty] and his father-in-law earned great respect as the father-in-law of one of the most respected scholars in the entire region [a rare and genuine description]

What is the best advice for him?
Start going crazy and return millions?
Or not?