What do the authors of Rolling Stone’s discredited story about rape allegations and the University of Virginia and New York magazine’s story about a high schooler with phantom millions in stock trades have in common?

Both the authors — Sabrina Rubin Erdely and Jessica Pressler — have spent time as staff writers at Philadelphia Magazine.

“What’s tough with both of these is these are two reporters whose work is highly praised,” editor Tom McGrath told Billy Penn on Thursday afternoon. “I’ve been surprised by what’s happened with both of them.”

McGrath, who joined Philly Mag’s staff in 2003 and became its editor in 2010, says he’s not examining the writers’ work for the magazine in light of the high-profile errors for other publications. And he sounded a note of sympathy talking about Erdely and Pressler.

“I know both of these writers personally, so I hate to think what they’re going through. The first thing that went through my head was there weren’t any issues (with the stories written for Philadelphia Magazine) where we know people had said ‘there’s an issue here,’” McGrath told Billy Penn, “Certainly on those pieces I worked on with Jessica Pressler, I’m 99 percent sure nothing was fabricated or fundamentally flawed.”

In general, McGrath says, the magazine depends on the public to contact the editors with questions or problems with their work. “My approach has been if people come forward and say this is wrong we’d be happy to look into things to the extent we can do it.”

That gets complicated, McGrath notes, with Erdely’s work — she was a staff writer from 1994-1999, a senior writer from 1999-2005 and a writer-at-large from 2005-2012.

“A national media company raised questions about a 1998 piece,” McGrath said, and he explained “I wasn’t on staff at the time. We hold fact-checking materials for a number of years but not 16 years. I can’t go back that far and do that.”

Meanwhile, Erdely is getting back in touch with her sources on the UVA story — and Pressler was set to take a new job at Bloomberg News.

Chris Krewson is the executive director of LION Publishers, a national nonprofit association that serves local journalism entrepreneurs build sustainable news organizations, and the founding editor of...