All three of those statements are false.
If you're "in the groove" so to speak with coding, continuing work could be much more productive. At the times he wishes to work later, his additional work could be dozens of times better than a typical day. In contrast, coming back to code you were in the middle of a day later can have an hour of delays as you work just to get back to the state of understanding you had before.
In this way he will produce more. Producing more sometimes leads to earn more (that one's not as definite). Learning more... well, the more projects you complete the more you get to do; the more chances to learn.
This isn't to say that having a fixed end time is bad, just that your statement is false.
