Moyes lost his temper after the match when he was quizzed about why full-back Van Aanholt was axed from the starting line-up just before kick-off.
The Sunderland boss claimed the decision was made for medical reasons but TV replays appeared to show the Sunderland defender reacting with surprise when he was given the news.
Van Aanholt, who was replaced in the team by 21-year-old loan signing Jason Denayer, later marched out of the ground unaided, refusing to answer questions.
Asked by Sky reporter Patrick Davison what had happened, Moyes said: “For medical reasons we chose to withdraw Pat.”
But he then responded to a follow-up question with stony silence, before losing his temper with the reporter off camera.
Moyes said later: “I won’t follow up if you don’t mind. I would like to try and be straight but I’ve given you an answer.