The comedian's lawyers said a lower court found probable cause this spring based solely on decade-old police statements, and they complained that defense lawyers had no way to challenge the allegations.
Cosby lawyer Christopher Tayback said prosecutors' use of the hearsay testimony rule "blows the doors off" due process.
"There is no rule that says, 'The court has to follow this rule, even if it violates due process,'" he said.
Montgomery County District Attorney Kevin Steele countered that the right of defendants like Cosby to confront their accusers in court doesn't apply at Pennsylvania preliminary hearings.
Steele told the judge he was using the 2013 rule change to spare Cosby Constand and other sex crime victims from multiple cross-examinations.
"It's our position that we're not going to re-traumatize victims at preliminary hearings," Steele told the judge, adding that he's using the rule change in a variety of sex assault cases, not just Cosby's.
Cosby, 78, was held for trial in May based on his and Constand’s police statements from 2005.
Cosby is charged with felony indecent assault and accused of drugging and molesting Constand in 2004. Authorities reopened the case last year after learning he had acknowledged in a deposition that he had given Constand pills and then engaged in sex acts with her.
They also considered the dozens of other women who have raised similar claims in the decade since Constand went to police in 2005.
Cosby calls their encounter consensual and describes the blue pills he gave her as Benadryl. He said he sometimes took the same allergy medicine to help him fall asleep.
Prosecutors chose not to have Constand testify at the May preliminary hearing, citing the 2013 state Superior Court ruling that allows hearsay testimony at that stage to spare accusers from repeated court appearances. However, the state Supreme Court has agreed to review the decision, leading Cosby's lawyers to challenge it. The high court has not said when it will hear arguments on the issue.
Constand told police the drugs left her semiconscious and unable to move. Her lawyers believe Cosby gave her something stronger than Benadryl.