The Chelsea manager witnessed his table-topping side suffer a blow in the race for the Premier League title, as a wonderfully inventive Fabian Delph goal secured all three points for Paul Lambert's men at Villa Park.
Chelsea had looked largely comfortable at 0-0 until Willian was shown a harsh second yellow card and subsequent red for tugging down Delph.
Further ill-discipline cost Chelsea in injury time when Ramires received his marching orders for a wild lunge on Karim El Ahmadi.
The challenge caused tempers to flare and Mourinho himself was subsequently asked to leave pitch side and enter the changing rooms.
The Portuguese questioned why Foy made that decision, and believes others should have been sent from the dugout, too, including Villa striker Gabriel Agbonlahor, who Mourinho accused of "aggressively" grabbing Ramires.
But the 51-year-old remained tight lipped when pressed on his views of Foy's performance, as he does not want to face ramifications from the Football Association.
"I don't make (a comment), I prefer not to make (one)," he said. "If I speak I'll be in trouble, I don't want to be.
"I don't want to do something we're not allowed to do. We're not allowed to speak about the referees. I don't want to be charged with bringing the game into disrepute, so I don't comment on any of the incidents of the game.
"It's a big occasion for me to know about the character of Mr Foy. I want to know what he is going to write about my sending off because if my sending off is because I was on the pitch then it was two or three metres inside the pitch.
"I think we had 10 people from the dugout (on the pitch). There was me, there was my two assistants, there was Agbonlahor, who came in and made an aggressive (act) on Ramires. He came from the dugout, he went to Ramires, he grabbed Ramires by the neck.
"I think almost all of us just (tried) to calm down and to try to stop the situation. So if I was sent off because I was on the pitch, I ask why not all the others? Especially one player who made an aggression on another."
Asked whether he sought clarification from Foy, he added: "He refused to speak to me. I tried to speak with Mr Foy twice. I tried on the pitch and I tried in the dressing rooms. I asked politely if I could have five seconds and he refused."
