Makes sense then. The smearing is consistent.
I have no experience with non-intermittent scanning. I’m drawing from past experience (video and old camera sensors not-for-industrial). In a moving subject, moving that slow, if you have a capture time that fast, it makes no sense that what you are seeing is the movement.
Another point corroborating above is that the smear is proportional to the amount of light. If it was just movement, everything would be be smear, not just whites. For example no smear on the blue clouds, only on the white letters of the Dreamworks logo. If it was movement, smear would be on the colors too.
Since the smear is bad, regardless of the film speed, and actually becomes well defined at slow speeds, it seems like the electronic shutter leaking (overflowing). Too much light?
To test that theory, you can decrease the amount of light, and slower shutter. If the theory checks, you should be able to find an amount of light that eliminates the smear.
It may be what the sensor global shutter can handle. I do not know if that is a limitation of the shutter or defect, FLIR tech support can weight on it it turns out to be too much light.
Hope the above observations give you some clues to find the issue.