When Leon went to Ida's apartment, he was wearing the same hoodie he wore when he went insane.
However, when Leon reached his apartment building, he noticed an unfamiliar car parked. Of course, he recognized that the car belonged to Liam at first glance. So, he took off his hoodie and burned it. Then, he buried the ashes in the ground and pissed on top of it to settle the ground level.
But now, he didn't have anything to wear, so he climbed to his apartment from the balcony, entered his room, and grabbed a t-shirt. Then, he jumped down and walked up the stairs.
He did all that while Anna was talking with Liam.
Even Anna wasn't aware of that. When she came into Leon's apartment early in the morning, she was surprised to see he wasn't there. She assumed he had gone off to kill some people as he hadn't killed anyone in a few days. She was happy that Leon had finally overcome his depression.