The goalless draw at the Liberty Stadium left both managers unhappy.
Paulo Sousa for the red card that saw Alberto Serran sent off in the first half and Neil Warnock for his side not taking advantage of the 10 men.
Sousa fumed: "It's not easy but we need to be strong to get above such things as has happened to us today. Perhaps the officials do not want to see us high up in the table.
"The sending-off was ridiculous and if standards of refereeing are not improved it will kill the game.
"We train hard and try to play good football and so I want to see good referees.
"l will not show him respect by speaking to him as he has not shown any respect to us by his actions today.
"I don't know if we would have won with a full side but we did make a number of chances."
Palace boss Neil Warnock was frustrated to claim only a point, feeling victory was there for the taking.
"I'm really disappointed because we had the opportunity to take all three points," he said.
"Sometimes it is more difficult to play against 10 men but we tried to go out for the win and could have done it in the closing minutes.
"I changed it around in the second half by putting on Alan Lee and Freddie Sears and they both could have done better towards the end of the match as they had clear chances to get us the victory."