Cremonese claimed their first win of the season as Daniel Ciofani's late penalty left Mourinho's side out of the Champions League spots in fifth place in the standings.
Mourinho, who was given his marching orders by referee Marco Piccinini at the start of the second half for dissent, said his reaction was caused by his treatment from the fourth official.
"For the first time in my career a referee has spoken to me in an unjustifiable way," the coach told a news conference.
"I'm not crazy. And to have the reaction I had is because something happened. I need to know now if I can do something from a legal point of view."
"Piccinini gave me the red because the fourth official told him so. But the fourth official doesn't have the honesty to also tell him what he told me, how he treated me and what provoked my reaction," added Mourinho.
Roma are fifth in the table with 44 points, one point behind fourth-placed Lazio. Cremonese, who won their first Serie A game of the season, moved up one place to 19th.
"We didn't deserve to lose," Mourinho said.
"The excuse of tiredness does not exist... The responsibility is ours, for a lack of intensity, lack of desire to close the game immediately."
"We paid too high a price, we didn't deserve to win but we didn't deserve to lose either. Especially for what we put in the second half, after the equaliser, we all thought we could win and then came the penalty episode."
