For another thing literally this man just gave 2 reasons why he would frame him and about 6 pieces of circumstantial evidence that CAN be proven to have happened even if Doumeki simply says it didn't. Meanwhile Doumeki so far presented ONE piece of circumstantial evidence against him that was called into question with these pieces of evidence. They wanted a scapegoat for something that as far as ANY of them know hasn't even actually fucking happened. So they can choose the guy who accomplishes their shit plans with no foresight and has a mountain of evidence pointing at the other guy.....or the guy who has a higher position and worse track record, who has made the call center worse since arrival, and has one piece of circumstantial evidence pointing at the other guy that may or may not be forged.
If this was a court of law the FIRST piece of evidence presented to claim it was Yariba wouldn't have stood since the guy presenting it had sole and total access to those records and permission to edit them.....also there would have had to be evidence a crime even happened in the first place. As opposed to vague rumors in their company that something bad was happening that after weeks they found no evidence of HAVING happened much less that there was a perpetrator. You can't just point a finger at a random guy and take him to court for 'killing your sister' when she's perfectly healthy and has no idea what's going on.