"We always said, 'You know, if her character pops, we'll bring her back,"' Carter Bays told The Associated Press on Thursday. "I thought she was great. I was very proud of that episode."
Spears, 26, garnered good reviews for her guest starring role as a goofy receptionist in the March 24 episode of the cult CBS sitcom. The show ended with Spears' character flirting with womanizer Barney (Neil Patrick Harris).
Asked if Spears might turn out to be the saboteur, Bays said: "Could be. There's no reason why not." He also suggested actress Sarah Chalke, who guest starred alongside Spears.
Bays said it was surreal to see Spears on the set.
"It was totally weird. ... I think we have a very, like, kind of Midwestern homey vibe here on the show, and it was strange to suddenly have helicopters circling," he said.
So will she or won't she come back?
"I don't know," he said. "I don't know the answer to that."
By Erin Carlson