Used to figure a laser was either working or dead, no in between, so I never bothered checking mine after a drop. Then I had a cheap one that started reading an eighth off over 20 feet and it cost me a whole morning resetting door frames, and now I check every time. I catch drift by marking a point at one end, shooting to the far wall, then flipping the laser around and shooting back to the same spot, if the return line doesn't hit my first mark I know something's bent. For vertical I hang a plumb bob next to the beam and see if they stay together top to bottom, and I do this before anything over 30 feet now.

Lighting is the one thing most people never think to check because it feels too simple to matter. That flicker pattern you caught is basically the software guessing at where shadows should land between frames, and it fails hardest on the neck and jaw where the curves change fast. A plain desk lamp angled from one side does the same job as your ring light, sometimes better, because a single hard light source makes every bad edge stand out. You can also just drag the clip into any editor and step frame by frame, but honestly the lamp trick works because your eye notices the jump before your brain can talk you out of it. Cheap tools plus slow motion beats expensive software most days.