Eric left the medical ward right after the nurse had released him. He didn't waste any time to back to the barracks because he was overly tired, even though he now felt great.
The evolution process made him even more tired than he was before. It was 3 o'clock in the morning. If we were to go to sleep now, he would get 3 hours of sleep before having to wake up at 6 o'clock.
Somehow he kept finding himself in situations that would keep him from getting enough sleep. His powers were much more effective and had an advantage at night. When he wanted to do something where he didn't want to get caught, after midnight was the best time for this.
