Additional shooters would have had the same challenges. I suppose exit wound data of the bystander would clarify when matched against the video forensics.
There are often times this position has tripped all of us up at certain points, particularly here. If there is no possibility that anything 'official' is ever communicated is accurate, it would seem that there is no hope at all for any of us and frankly why bother waking up tomorrow nor caring for any day past tomorrow. That overly dramatic comment out of the way, I do believe that most of those that have networked over the years here have developed a strong ground, a strong intuition and the ability to remember to be objective as much as our chemically altered bodies will muster.
Occum's razor principle helps to add one side of the spectrum of possibilities, which the rest of the spectrum including all sorts of variables, seen and unseen.
So with that statement, if above mentioned capabilities are unknowable, why would one speculate on it?
There do seem to be some laws that exist at what is called dimensions, densities, realms and so on, which tend to all have something to do with magnetism/gravity. While I do not discount there might be something on some plane, to exercise "bullet-time" (ref: the fourth Matrix movie) type of capabilities, speculating on or trying to prove it, doesn't seem to be a good use of our time down here in the soup.