The sources say the $130,000 given to Carter in severance was not a lavish plum for a half-year's work, but had been written into the contract as the severance fee regardless of his departure date.
"He did not leave voluntarily," one of the sources, who spoke on condition of anonymity, said Friday.
"The chief of staff is a crucial position in government. It's the premier's right-hand man, so to speak.
"That has to be someone that without a doubt can help the premier move the government agenda forward. In this case it was not the right fit."
When asked about the details of his contract Friday, Carter emailed back a two-sentence reply: "My severance was 130K. Trust you are well."
Journalists and opposition parties have been trying for a year, through freedom of information requests, to determine what Carter received in severance after he stepped down as chief of staff in Redford's office in early 2012. He had been in the job for about six months at an annual base salary of almost $265,000.
Carter went from the chief of staff post to serve as a strategist on Redford's Progressive Conservative party's election campaign, which resulted in a PC majority government.
Journalists seeking the severance information were stymied by bureaucrats in Redford's office who refused to release it, arguing it could harm Carter's business interests and be used as fodder by political opponents to smear him. They also argued that releasing the figure would make it harder for the premier's office to attract high-end talent.
The issue eventually reached the office of Alberta's privacy commissioner. Late last month, the commissioner directed that the information be released, dismissing arguments it would harm Carter's interests or prevent the premier from recruiting top people.
On Wednesday, Global TV reported that officials in Redford's office had chosen to defy the privacy commissioner, an independent officer of the legislature, and keep the severance figure under wraps. That revelation led to a storm of criticism toward Redford, despite her argument that, as a politician, she is not allowed to intervene in freedom-of-information issues because of the firewall rules preventing political meddling in the process.
The NDP and the Wildrose Party noted that Carter was not just any chief of staff. In 2011, he had successfully run Redford's campaign for the PC party leadership to replace outgoing premier Ed Stelmach.
Redford, with almost no support in the PC caucus, had been considered a longshot to defeat the heavily favoured Gary Mar. But Redford and Carter leveraged support for her on social media and, with a last-ditch promise to restore education funding cuts, edged out Mar on the second ballot to win.
Redford took over the premier's chair and brought Carter in as chief of staff.
Both Wildrose leader Danielle Smith and Brian Mason have said the absence of details on the terms of Carter's employment raises the question of whether Redford lavishly overpaid his severance as a way to reward him for his services.
Redford dismissed those accusations Thursday, but as opposition outrage spread in newspaper websites and on radio shows she announced a new initiative late in the day.
She ordered Don Scott, the associate minister in charge of accountability, transparency and transformation, to begin a review of severance disclosure procedures outside the freedom-of-information process with an eye to releasing more information.
That didn't quiet critics, who demanded Redford release Carter's severance figure immediately to conform with her manifesto promise to run an open government.
While Redford refused, Carter himself supplied the answer, announcing the $130,000 figure on Twitter early Friday.
That led to a renewed round of criticism, with opposition leaders demanding more details on the terms of Carter's employment in order to quell concerns over why and how it was paid.
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