SAN FRANCISCO — When Luke Brugnara represented himself during a bizarre art fraud trial in May, the fallen real estate magnate frequently railed that the art he was accused of stealing was “fake” and essentially worthless. That argument didn’t carry much weight with the federal jury that convicted Brugnara.

But at an evidentiary hearing on Wednesday, a government expert conceded that much of the art at issue in the case has “no commercial value.” The hearing led U.S. District Judge William Alsup to muse aloud about how the prosecution might have turned out had Brugnara relied on counsel rather than represent himself.