Samba got caught napping in first half stoppage time and Danny Welbeck stole the ball and took off towards the goal only to be brought down just outside the penalty box by the big defender.
"I have no complaints on the rule or the law," Allardyce said.
"Chris got himself in a muddle and pulled Welbeck back. It was the correct decision, outside the box and he got the red card that I have got no complaints about."
He added: "Chris is an immense talent and his ability on the floor is normally very, very good. On this occasion he got himself mixed up.
"Instead of just clearing it with his left foot, he decided he wanted to do a little swivel round and get it back to the 'keeper but Welbeck nipped in and caught him out.
"He will be a big miss but Jonesy (Phil Jones) went back there into his natural position and did an outstanding job in the second half.
"Him and Gael (Givet) and the whole team did very well getting a well-earned point."