I have seen pellets have pretty erratic flight pattern, not least the Beasts trying to shoot those far, so you can have them be like lasers at 50 M, but change aim for 70 - 80 M and its like when they pass the 50 M mark the pellet start to spin / whirl around.
When the sun are just right and you shoot at a darker area it is very noticeable. so it could be they also whirl around at the 50 M target but i just do not notice it as it is a brighter backdrop VS the back corner of the field i shoot to when i max out the distance.
First time i saw it, it was a big WTF moment, and there was no doubt in my mind why i was not hitting anything at the longer distance.
I have also seen some footage on youtube where the pellet just seem to wobble in flight, but what i saw was like a semi opaque metallic disk going off into the distance.
The wobbling pellets i think you need a slow motion camera to capture it.
I think it was in one of Teds videos from way back i saw the wobble, but i cant recall seeing a video with the wildly spinning i saw.
The video of the lucky reptile, the shot seem to drop quite a b it behind it.