Cardiff manager Dave Jones despaired at referee Uriah Rennie after his side's 1-0 defeat at Bristol City.
Jones has had run-ins with Rennie in the past
Rennie sent off Bluebirds striker Steve Thompson early in the first half for a tackle from behind.
Jones says Rennie was inconsistent, that keeper Kasper Schmeichel was taken out before the Robins' goal and that he denied Cardiff a penalty near the end.
"I've had so many run-ins with him (Rennie) that I'm wondering if it's personal," Jones told BBC Sport Wales.
"Again after the game I've taken him a tape and told him to watch it again because it's not acceptable.
"It wasn't the best performance from him, but the referee and the assessor will protect each other.
"Credit to Bristol City, but Rennie spoilt the game as a spectacle and it's hard when decisions don't go your way."
I enjoyed the stick from the Cardiff fans, it fires you up and lets you know you're out there
Meanwhile, Robins striker Lee Trundle claimed a hand in Marvin Elliott's goal that gave his side the Severnside derby win.
"It hit me on the shoulder and went in," said Trundle, whose unhappy relationship with the Cardiff fans dominated the build up to the game and who was baited mercilessly throughout.
"I'll take any goal, but I'd have to be pleased if they awarded that one to me!
"I enjoyed the stick from the Cardiff fans, it fires you up and lets you know you're out there.
"Things haven't been easy for me at Bristol, being in and out of the side, but I'm not one to give up, I'll keep working hard."