A Pennsylvania appeals court on Monday questioned why actor Bill Cosby never got a supposed non-prosecution agreement in writing as his lawyers asked the panel to overturn his sexual assault conviction.

Cosby, 82, is serving a three- to 10-year prison term for drugging and molesting a woman at his home in what became the first celebrity trial of the #MeToo era.

The three-judge panel asked why Cosby’s top-shelf lawyers didn’t follow the norm and get an immunity agreement in writing, and approved by a judge, when accuser Andrea Constand first came forward in 2005.

“This is not a low-budget operation. ... They had an unlimited budget,” said Superior Court Judge John T. Bender. “Could it be they knew this was something the trial court would never have allowed?”

Cosby’s lawyers have long argued that he relied on the promise before giving testimony in Constand’s 2005 lawsuit that proved incriminating when it was unsealed a decade later.

Judge Carolyn Nichols echoed Bender’s point, asking, “how can the elected district attorney bind that office in perpetuity?”

Cosby’s lawyers also attacked Montgomery County Judge Steven O’Neill’s decision to let five other accusers testify when Cosby went on trial last year, after more than 60 accusers came forward and his deposition was unsealed. Prosecutors said they chose women whose accounts showed that Cosby had a “signature” crime pattern. Bender seemed to agree, interrupting defense arguments that their stories had significant differences.