"Despite Judge Engoron's critical role, Mr Trump was combative on the stand. He took direct aim at the judge, leading to some heated exchanges, and drew his rebukes for airing broad grievances when they were not directly relevant to the question.
All of this appeared to irritate the judge who will, ultimately, decide on any penalties.
"It does seem completely counterintuitive. Especially when the judge is going to be the finder of fact and law," Kevin McMunigal, a former federal prosecutor and professor of criminal law at Case Western University, told the BBC.
"There are only two explanations," he said. "One is Trump just can't control himself. Or two: Maybe this is something he has thought out."
So if Mr Trump's team has adopted this antagonistic approach as a deliberate strategy, what could the goal be?
"I think he is trying to goad the judge into doing something he can argue on appeal shows prejudice on his part," Prof McMunigal said. "Maybe he makes a comment they can use to support a bias case later."
www.msn.com/en-us/ne ws/world/why-trump-m ay-have-deliberately -provoked-judge