Donald Trump has in the past used his courtroom testimonials to spread his beliefs about election interference, but on Thursday his testimony in the E. Jean Carroll case was limited to about three minutes in which he was mostly kept in line. That's in part due to a smart technique by Carroll's attorney, an ex-prosecutor said on Thursday.

The former president's brief set of answers were no accident, according to former federal prosecutor Renato Mariotti, who often appears on MSNBC.

Mariotti on social media specifically highlighted a move by Carroll's lawyer, Roberta Kaplan of Kaplan Hecker & Fink LLP.

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'Very savvy move by Robbie Kaplan to resist the urge to ask many questions of Trump," Mariotti said, adding that Trump has a tendency to take a mile when given an inch.

"Any questions she asked would give him an opportunity to riff on irrelevant subjects and get his story out in front of the jury, which he and his lawyer haven't done well otherwise," the expert added.

Union lawyer Michael Murphy responded to Mariotti, saying, "Why not get him to wax melodic about his immense wealth?" Such testimony could potentially undercut the ex-president in another civil case.