Is the action of a man who sleeps until 10 AM and prays after waking up, believing this to be correct based on a fatwa from an imam, right?

The Middle Prayer is the Asr prayer. The Fajr prayer holds great virtue, and persistent abandonment of it is a sign of hypocrisy. The time for Fajr ends at sunrise, and deliberately delaying it is a grave sin. A person who is sleeping should take measures to wake up; if they do so and wake up after sunrise, there is no sin upon them, and they should pray whenever they wake up. However, whoever intentionally misses it is sinful. What this man is doing is negligence and dereliction of duty, and he must be reminded of the obligation to observe prayers at their prescribed times. The Fajr prayer he performs, if it is a make-up prayer, is obligatory according to the majority of scholars, along with repentance if he was negligent. Some scholars, however, hold that whoever deliberately misses a prayer until its time has passed, making it up will not benefit him, and he must offer sincere repentance and increase in supererogatory prayers.