In 2016, he convened a franchisee meeting in a Sacramento warehouse. He told everyone that Subway wanted to improve its strongest restaurants and shut down the weaker ones, according to Nikku Aulakh, a franchisee who was present.

She left the gathering alarmed. She and many fellow franchisees had been pushed for years to invest huge sums in new stores that were now struggling. Subway’s franchise contract forbids the company from unilaterally closing stores just because sales are weak. But franchisees can lose control of their restaurants for failing to meet Subway’s operating standards — violations cited by inspectors employed by development agents like Mr. Patel.

Ms. Aulakh said Mr. Patel eventually pressured her into closing or selling her four stores in Sacramento, after they received a slew of bad evaluations. “I would have liked to stay in business for another 10 to 15 years,” she said. “I wanted to make more money, but I had no other choice.”

Vishal Sharma, a franchisee in Nevada who owned three stores, described another meeting that Mr. Patel convened in Reno the same year. In front of some 20 store operators, Mr. Patel said that he had “the money to buy the best lawyers,” Mr. Sharma recalled. “At the time, we weren’t scared. We thought that maybe that was just his style. Then we figure out that this guy’s template is not developing the territory, it’s taking away the territory.” (Mr. Patel said in an email that he had been informing the franchisees that Subway’s lawyers were available to answer legal questions.)

At one point, a franchisee sent Mr. Patel an anonymous complaint; he responded with an email to a large group of them, which was reviewed by The Times. He threatened a lawsuit that “would be so huge it would nearly take all of your life earnings in Subway in fighting this suit. Please don’t test me especially when you don’t have any basis.”

Subway terminated Mr. Sharma’s contracts in 2017. Last December, in state court, he accused Mr. Patel of using “rigged compliances” and Subway of employing an “unusual structure where the local agent is a supervisor, as well as a competitor.” The case was ordered into arbitration in Connecticut, but Mr. Sharma is appealing the decision.

Ms. Husler, the inspector who called herself Mr. Patel’s “hit man,” said that Mr. Patel considered his own interests when determining what stores would be sent to arbitration, and likely closed. When it came time to conduct inspections, she said, Mr. Patel made it “very clear that his stores were to pass” and that “the people he wanted out of the system were to fail out of the system.”