The San Fracisco 49ers have hired Jim O’Neil to be their defensive coordinator — but he didn’t leave a great impression at the Cleveland Browns where he formerly served as coach.

O’Neil, who will serve under new head coach Chip Kelly after Kelly was let go from the Eagles, has a strong reputation as a defensive coordinator, helping to improve Buffalo’s defense in 2013 and boosting the Browns’ defense to a respectable one in his first year in Cleveland, according to a NinersNation.com report.

But 2015 proved to be a disaster for the Browns, as the team got worse on defense and players told a reporter it was O’Neil’s fault. Specifically, the players complained that the Browns’ defensive linemen were being told to play based on how the offensive linemen were playing them, leaving the linebackers to basically guess how the defensive line would rush. Apparently, this flaw was repeatedly used against the Browns by other teams, and it was especially bad in run situations.

O’Neil, however, told reporters that it was up to the players to do their job and execute their roles.

In addition, the Browns faced a number of injuries to star players, including Joe Haden and veteran Donte Whitner. And the 2014 defense had a great secondary but a bad rushing defense, so even a slight decline in the pass coverage could result in a tumble in their defensive rankings.

But the report also put forward the possibility that O’Neil was good sometimes because of other coaches’ success, not his own.