Even after hours had gone, Marcel's mood still had not improved and so to prevent transferring his aggression to the others, he buried himself in paperwork in the office. Choosing to use accounting to distract himself.
He was not a man who let his emotion run amok but he has become loose with most of his principles ever since Arianna arrived here. Maybe it was not entirely a bad thing to back down a little. He could use this break to rethink and remold himself as the person he once was - someone who wasn't weakened by one woman.
No wonder his father never wanted him to feel this way. Marcel was not sympathetic to his father, Daniel's actions, but he could see a little reason there. Love made them weak, and a quick example was him making dumb decisions like falling for the girlfriend of his nemesis, Elijah. Yep, his father would be super proud of that - note the sarcasm.