"The company, the management and me personally — not the store manager — are culpable and responsible. And we're the ones to blame," Schultz said Thursday.
"We were absolutely wrong in every way. The policy and the decision she made, but it's the company that's responsible," he added.
Schultz said the company had a "loose policy" around letting paying customers use the bathroom, though it was up to the discretion of individual store managers.
The company responded to the incident by announcing that it would close its more than 8,000 U.S. locations on the afternoon of May 29 for racial bias training. Schultz said on Thursday that the company brought in outside help to design the curriculum.
Sherrilyn Ifill, president of the NAACP Legal Defense and Education Fund, is one of those helping to shape the training.
"Racism is deeply entrenched in our society, and any real effort to confront it means you have to be in it for the long haul," Ifill told NPR's All Things Considered last month. "It means you have to be in it seriously. It means not just training. It means monitoring the effectiveness of that training."
Schultz claimed that that was the case, saying the May 29 session is "the beginning, not the end of an entire transformation of our training at Starbucks."
He said the company was also working with Stanley Nelson, director of the documentary Freedom Riders, to produce a documentary that would "make sure that people understand: This is not a marketing thing, we're deeply committed to this."
Schultz also addressed the company's past failure to address racial issues in the U.S. with its short-lived "Race Together" campaign in 2015. The company had encouraged baristas to write "Race Together" on customers' cups in an effort to start conversations about race.
He said the goal was to "elevate the national conservation, the national discourse around race" after the killings of Trayvon Martin in 2012 and Eric Garner in 2014 had brought up "racial divide."
Starbucks held meetings among employees about race, involving workers sharing both "their pain" and "their bias," Schultz said, which spurred the idea for some type of outreach beyond the company's workers.
It didn't last one day.
"Within two hours, the entire initiative was basically hijacked by social media. Hijacked by hate, by anonymous people who just pretty much stole the narrative," Schultz said. They shut it down quickly after, mostly out of concern for safety of the company's workers, he said.
NPR's Code Switch rounded up reactions at the time, many of which called the campaign ill-conceived and too sensitive and complex a topic to start with a coffee shop cashier.