Cameroon striker Samuel Eto'o earned Inter a point with a goal at the start of the second half after Mirko Vucinic had put Roma ahead with a header early on.
"The match was close to terrible," Mourinho told Sky television. "All three teams were close to terrible.
"One team tried to win, but didn't do enough to. Another side did not want to win.
"As for the third team - it was an easy match to officiate, four or five blows of the whistle would have been enough, but he blew up 40 or 50 times."
Roma boss Claudio Ranieri said the referee was defending the visitors from Inter's overly physical approach which left Italy midfielder Daniele De Rossi needing surgery on a fractured cheek bone after a first-half clash with Frenchman Patrick Vieira.
"De Rossi needs an operation and it's thanks to Vieira. He often goes up with his elbows high," said Ranieri, who had a series of spats with Mourinho last season when he was in charge of Juventus.
"They committed twice as many fouls as us and maybe they should have been pulled up more," he added.
"It was systematic. Every time we tried to counter-attack and they were in difficulty they brought us down. The referee has to reward the team that tries to play football."
However, Ranieri denied holding a grudge against Mourinho, who replaced him at Chelsea.
"He's a great communicator. He turns things around and he's always right," he said. "But it's not true that I don't like him. It's fun."
