In the early days of their partnership De Niro would often yell at him out of anger and frustration, Mr Harvey testified on Wednesday in a workplace discrimination trial brought by the actor’s former personal assistant Graham Chase Robinson in New York federal civil court.
Ms Robinson is suing the Flowers of the Killer Moon actor for $12m (£9.9m) for allegedly causing her “extreme emotional distress and reputational harm” during 11 years working at his vanity company Canal Productions.
De Niro, 80, claims in a countersuit that his former assistant stole five million air miles from his company, racked up $35,000 in unauthorised Uber trips, and paid for expensive restaurant dinners and fancy groceries on her company credit card.
On Wednesday, Mr Harvey took the stand to give his experience of working as a long-term employee of De Niro, and said he had never witnessed De Niro’s anger directed at Ms Robinson.
But perhaps more interestingly for movie buffs, Mr Harvey shared fascinating anecdotes about some of the Oscar-winning star’s biggest roles.
He told the court how he began working with the screen legend in early 1984. De Niro was struggling to lose the 35 pounds (16kgs) he had put on for his role as boxer Jake LaMotta in Raging Bull, and sought out the former ex-University of Maryland wrestler’s services.
He became a full time personal trainer for De Niro in 1985, and would work out with the actor nearly every day and travel with him to film locations all over the world.
“I like working for him because he’s a very disciplined man who works hard at his craft and I respect him very much,” Mr Harvey told the court.
Mr Harvey became De Niro’s trusted confidante and dialogue sparring partner. The pair would work out for hours more than 300 days a year at De Niro’s properties in New York City, Montauk, and upstate New York. Afterwards, the pair would recite lines on upcoming movie projects for several more hours.
“He might want to look gaunt or sometimes overweight, sometimes muscular. We worked accordingly,” he said.
The first of their 93 films working together was the 1984 romantic drama Falling in Love, starring De Niro and Meryl Streep.
Asked to recall memorable films he had worked with De Niro on, Mr Harvey first cited 1991’s Cape Fear.
At the age of 48, De Niro reportedly went on a high-carbohydrate diet of brown rice and green vegetables to fuel marathon workout sessions of chin ups, push ups and up to 600 crunches a day.
“It was impactful because he was playing a character who had recently got out of prison after many years, and he had to be defined and cut and muscular,” Mr Harvey said.
For Goodfellas, De Niro’s mob hitman character Jimmy Conway had to age by several decades midway through the shoot, and so Mr Harvey devised a rigorous three-week training programme to make him look “old and gaunt”.
Mr Harvey said his role broadened from workouts to dialogue training, and he would accompany De Niro to table reads of prospective scripts and during hours of role-playing scenes.
Mr Harvey said he was told he had “good rhythm” for the dialogue.
In the 2008 drama Just What Happened, Mr Harvey told how he recited lines on the other end of a phone while De Niro’s character was supposedly talking to his ex-wife played by Robin Wright.
De Niro was a “generous” boss, he said.
He started out on a salary of $55,000, which eventually rose to $375,000 a year by 2019, and would receive a week’s salary bonus on his birthday and at Christmas.
He was forced to spend long periods away from his family in California while working with De Niro at his homes in New York, or filming on location everywhere from Colombia to Australia.
Working days typically started at 3.30am, with the pair rehearsing De Niro’s lines for several hours before filming began.
“There was not a moment to waste,” he said.
During testimony last week, Ms Robinson, who earned $300,000 a year, said she approached De Niro seeking the same salary as Mr Harvey.
The actor supposedly responded: “Chase you don’t have kids. Dan has a family to support.”
Ms Robinson also alleged she was forced to carry out “demeaning” tasks such as washing De Niro’s bed sheets and gift shopping for his seven children, which she felt was stereotypically women’s work and evidence of gender discrimination.
Earlier on Wednesday, Ms Robinson’s attorneys rested their case and the defence called forensic psychiatrist Kimberly Resnick to the witness stand.
Dr Resnick, who testified she earned around $90,000 for her work on the case, interviewed Ms Robinson for seven hours and reviewed her work and psychiatric records.
She refuted earlier testimony from Dr Robert Goldstein, who diagnosed Ms Robinson with “generalised anxiety disorder” that arose from her time working for De Niro.
Dr Resnick said that the former assistant instead showed “traits of narcissism, paranoia and grandiosity”.
“While Ms Robinson was reporting symptoms of stress, they were in the realm of normal human reactions and responses to stressful events,” she said.
After Mr Harvey’s testimony, the defence rested its case and closing arguments were expected to begin on Wednesday afternoon.