Jean said Monday that his comments revolved around lessons he had drawn from his successes and failures in life. He urged students to pursue their dreams and practice good communication.
But what some students heard most clearly were claims Jean made about himself that they deemed unbelievable, including that he was drafted by the Phillies when he was 16.
So, during the assembly, students used their cellphones to look him up on the Internet, and to share their findings on social media websites.
They learned about his earlier business venture called SwingFest Events, which organized adult lifestyle conferences.
Principal Robert Schultz, who joined the school in July, said the initial contact with Jean came in January 2013, when Jean got in touch with the guidance department to offer his services. Schultz said he did not know if anyone did a background check on Jean at the time, and would not say if one was done this year.
Schultz said students who heard Jean last year praised his presentation, which led administrators to invite him back.
On Tuesday, Upper Dublin Superintendent Michael Pladus said the district has a policy for outside speakers. "The teacher/sponsor and school building administrator are expected to exercise judgment and to investigate fully any proposed resource persons," he said.
Jean disputed student accounts of his speech on Thursday. He said he routinely admits successes and failures and uses them to teach adults and young people strategies to achieve their goals.
And the "adult entertainment" businesses?
He said he got into that industry "by sheer fluke of an investment." Before that, he was in construction, Jean said.
Jean relinquished those businesses around 2010, the year he filed for voluntary bankruptcy in U.S. District Court in Harrisburg. The case was discharged last year.
So what if he did own such businesses, he added. He did not - and would not - talk to young people about them.
Besides, he said, "it's just another business. . . . We just looked at it from the perspective, we obviously were making money."
Jean said he never has claimed to be perfect. Teachers, parents, or anyone else at Upper Dublin who disapproves of his background should look in a mirror, he said.
"Can you tell me that no one in that school has a DUI?" he said. "No one in that school has ever cheated on his husband or wife, that no one has ever been arrested?"
Bea Cubit, president of the school's Parent Teacher Organization, said that she did not blame the administrators for the incident and that only a few parents voiced concerns to her.
Pladus said the district had learned a lesson from recent events.
"The experience . . . certainly confirmed the immediacy with which information can now be accessed, and the importance in the future of carefully vetting all speakers with the same due diligence that we employ in hiring."