So what happened? Why is NCR (NCR) paying $1.65 billion to buy Digital Insight from private equity in November, rather than bidding $1.1 billion or so back during the summer auction? And was this Thoma Bravo’s plan all along, despite its original promise to “build the business organically and through strategic acquisitions?”

Sources familiar with the situation tell Fortune that this quick flip may actually have more to do with Intuit (INTU) than with either Thoma Bravo or NCR.

Specifically, Intuit was intent on selling Digital Insight at warp speed – including a 30-day final close (which ultimately caused Thoma Bravo to fund the acquisition via bridge loans, before later lining up more traditional financing). That basically knocked out strategic bidders like NCR, which typically need much longer lead times than does private equity (several PE firms submitted bids).

But NCR did not plan on giving up so easily. It reached out to Thoma Bravo after the original deal was announced on July 1 (the close was announced on August 1), and formally began acquisition talks by early October.

For NCR, the idea was about fundamentally changing its largest line of business, financial services, by permanently making it multi-channel. Thoma Bravo had been sincere in its original comments on growth plans for Digital Insight, but ultimately could not turn down such a sizable return in such a short amount of time.

Neither NCR nor Thoma Bravo accepted interview requests, in part because the deal has not yet closed.

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