I’m not one hundred percent sure on this but re: the first image… that is actually one of the 3 FX shots that was tweaked between May 1977 and June 1977 while the film was still in theaters. Among other improvements, ILM re-timed the flash frames, so that frame could potentially come from the earlier version.
Most fan preservations are based on the June cut (as are all modern home video releases) but the original version of the shot did make it to a couple of early releases, including some laserdiscs. Sadly, I don’t think it exists in HD anywhere. But laserdisc could be marginally better than what you’ve got now?
Again, not sure that’s what’s going on here but it’s worth checking out.