A onetime Chicago billionaire recently tried to make a quick exit when faced with being served court papers — but apparently not quick enough.

Earlier this month when a private detective tried to hand Chicago’s newest billionaire CEO Rishi Shah a summons to face a lawsuit filed in New York alleging he misled investors — Shah ran away and jumped in a waiting Cadillac Escalade and shut the door.

A private detective had staked out the mansion Shah calls home in the 900 block of North Clark Street on Nov. 12 and caught up with him as Shah left at 10:25 a.m., according to recently filed court documents.

Rishi Shah

Rishi Shah is a co-founder of Outcome Health | Photo by Steve Becker photography

Shah, 31, bolted when approached by Scott Rabin, the private eye hired to serve the summons.

“While Mr. Shah sat in the Escalade, I knocked on his window and again identified myself,” Rabin wrote in a court filing detailing the encounter.

“I placed the pleadings and the subpoena on the roof of the Escalade.”

When Shah’s driver pulled away with the paperwork still on the roof, Rabin followed in his own car and snapped a picture for good measure.

At a red light, and through rolled down windows, Rabin told Shah’s driver about the papers waving around in the wind on the roof of his vehicle and “that his passenger, Mr. Shah, was served.”

Shah’s spokesperson Davidson Goldin, reached Monday via email, said the whole thing was a misunderstanding.

“Rishi was not aware the person banging on the door was trying to serve papers,” Goldin said.

Shah, who’s been hailed as the darling of Chicago’s startup scene, faces a lawsuit filed earlier this month by investors — including a fund co-founded by Democratic gubernatorial candidate J.B. Pritzker and units of Goldman Sachs and Google — for allegedly misleading them about the company’s sale success.

In June, Forbes estimated Shah’s net worth at $3.6 billion, although it’s unclear how his recent legal troubles has affected that number. For now, he is not on the list.

Outcome Health installs video screens and tablets in doctor’s offices that offer videos and interactive features during patient visits. Outcome Health profits by also offering the screens as an advertising platform to drug companies.