GMM- Why true a wheel to a few thousand thousandths of an inch only to mount a tire that's off by a few mms? (That was said, more or less, by the head of Santana about 30 years ago as a reason he never used sew ups..) Another words, it's all relative. And how the related dimensions/alignments line up are the real ride effect. As an example one could have a frame that was off center but a wheel that was dished to compensate. the tire contact point with the ground would be in line with the BB and ft wheel but it would look all cock eyed to the rider in it's draft.

Eric is right to question how the stated dimensions were measured. My coworker thought that the carbon frame he was building up was off before he learned that the seat tube was asymmetrical by design. Rendering the string test invalid. A best test would have the wheel's alignment measured (think of two pairs of very long straight edges running along either side of the rims parallel to the ground front to back, one set a few inches off the ground and the other set a few inches below the rim's tops). Then all frame issues between the wheels would not matter excepting those that misaligned the wheels ONLY.

How "straight" a carbon frame (or fork) is is a debate. How straight it needs to be before a rider will notice it when riding is another debate. (I've had riders say one thing about their high buck bike then change their tune after showing them the alignment issues that existed). As a guy who works with steel I can get the frame/fork to measure real straight using traditional builder alignment methods but still have any one rider not be able to ride no handed without leaning a bit to one side or the other side.

Did you ride this bike?

I will agree that it seems that the frame was not well aligned. Certainly a big enough question in your mind to not have it satisfy you. This lack of confidence is enough a reason to reject it.

So many assume that a molded frame is as straight as the mold is... Andy.