Not to worry.
I've had that happen with a larger quail early on. It is not a regurge at that point, they are simply recognizing the prey is too large and are backing out of it. A true regurgitation would take place after the digestion process has started. There could be a number of reasons why the snake backed out, but that's all it did. Back out.
Now if you were to see this happen a day after feeding or even a few hours, it is a different situation.
I would doubt you'd have any issues if you fed in less than a week, or even 2 days.
Unless something happened during the feeding that you are not aware of I'd say you have nothing to worry about.