Nonsense. And to understand why, imagine that instead of being far away, the plane was instead a couple of hundred meters from the camera, and think about what it would look like then. Would the image be completely obscured by a blob of "hot gases" several stories high? Why or why not?
On top of what Gtoffo posted, I think the aircraft was added to the blob later and may not be exactly to scale...
Here's a video showing the true ratios between an aircraft and its blob:
Here's my take on the `glare vs hot gas' matter:
What is perceived as "lens glare" in FLIR images is probably "CCD bloom". It looks the same, but has a different cause and happens in a different area of the FLIR (the CCD instead of the optical system).
You will hardly find any references to `IR glare' (except on Metabunk of course), because the absence of glare is considered as one of the unique selling points of FLIR camera's:
Thermal cameras aren't affected by visible light, so they can give you clear pictures even when you are looking into the setting sun. In fact, you can aim a spotlight at a FLIR and still get a perfect picture.
FLIR's seem to demonstrate glare, though, but what you see is something else, something happening in the CCD instead of in the optical system: Blooming:
Each pixel in the CCD catches IR photons and transforms them into electrons (resulting in an electric charge).
At saturation, pixels lose their ability to accommodate additional charge. This additional charge will then spread into neighbouring pixels, causing them to either report erroneous values or also saturate. This spread of charge to adjacent pixels is known as blooming and appears as a white streak or blob in the image.
In addition, because this extra-large number of electrons needs to be moved down the sensor in order to be read by the CCD readout register, moving this saturated spot causes a vertical streak/smear down the image.
Source:
https://www.photometrics.com/learn/imaging-topics/saturation-and-blooming
This means that a certain heat source can occupy more pixels than its true size if the corresponding CCD area is bombarded with enough IR photons, causing the pixels to saturate and to saturate their neighbours as well.
The heat from jet engines, for instance, can occupy more pixels than its true size because of saturation of the CCD area where the IR photons hit. This will typically happen if the photons hit a tiny area of the CCD, like when you create an image of a jet far away and all the IR photons emitted by the jet engines hit a small spot on the CCD (see video above):
If you zoom in or out with the optics of the camera, the number of IR photons entering the camera does not change since that number is determined by the entrance pupil of the camera. However, these photons are distributed over a larger CCD area if you zoom in, because the optical system basically projects the zoomed image on the CCD. Zooming in will lead to less bloom because each pixel in the CCD now has less photons to absorb.
The engine blobs now are close to the real size you would expect from the hot air behind them (see video above):
How does this change the "rotating gimbal" hypothesis?
Since hardly any `glare' is created by IR optics, simply assuming a bright IR source causing glare in the rotating Gimbal optics does not work.
A small irregularity on the ATFLIR wind screen then?
I don't think so, since the wind screen basically coincides with the entrance pupil of the ATFLIR. This essentially means that every pixel of the image created in the CCD is made from rays emitted by the corresponding outside area hitting
every part of the surface area of the primary mirror. In other words, every pixel uses the whole surface area of the primary mirror to be created. Any irregularity in the corresponding wind screen area will not hinder the creation of any of the CCD pixels much, it can at most create some stray light showing up as a veiling glare on top of the image while the image is still recreated perfectly pixel by pixel.
A large irregularity on the wind screen maybe?
This would affect
every pixel of the image and cause an almost equal blurring of the whole image, since the wind screen basically coincides with the entrance pupil of the ATFLIR (see explanation above). I do not see this in the ATFLIR images.
That's my take, folks. Take it or leave it, but I've spend enough time already on this topic. We'll see what the Pentagon report will bring, which will provide a more holistic view on the subject matter I guess, without any definitive answers yet.