The funniest thing about this is that the people who shriek most about 'fake news' won't actually care if this has been deliberately altered. What a wonderful time to be signalling virtues:
Several separate issues for me.
The main one would be, is it OK for reporters to push away the hand of an intern who was taking the mic? Does it make a difference if the intern is a woman?
Was the video edited to look slightly worse?
If so, that would be slightly disturbing (but it's also disturbing when the BBC does it).
Then the question would be why bother? If the reporters shouldn't be pushing interns arms out of the way and the original clearly shows this, wouldn't posting a video with three missing frames undermine the case, especially when existing footage is everywhere.
The next question is what caused the video to differ from the original. Was it a deliberate edit? Did someone sit and think about how this could be altered to fit a narrative, and then compressed it down to a tweetable size? Or is it something that happened in compression and transmission. Which are the B frames, which are the I frames? Could it be an interpolation error on transcode, and whose transcoder?
I can see why info wars would have picked it up - even if it was a natural glitch, and maybe especially then. If you see video, pictures or posts that match what you expect and that proves your point, you retweet and repost with a flourish and an "Aha! Told you so!" That's completely normal and I've come to expect that from all sides.
So, it could be as simple as : some people are sharing the CSPAN clip showing that Acosta obviously pushed the intern's arm away and somewhere along the line a transcode glitch lost 3 interpolated frames making the clip accidentally more mimetic causing it to spread in the echo chamber that both Alex Jones and the Trumpets inhabit. That's disturbing in that those two are in the same chamber, but it's different from nefarious - but it's also the difference between making the rather dull claim that the video they posted was defective versus the panic and crowd motivating claim that the administration is deliberately manufacturing evidence.
The latter theory I think is on a par for likelihood with a theory like: infowars and through them, the Trumpets are being pranked by spreading a video that is virtually indistinguishable from the original but which differs on a frame by frame analysis - a bit like the Killian memo that torpedoed Dan Rather, which, if they were truly faked may have been faked as a poison pill to undermine the credibility of the general facts of the story.
If the video has been deliberately altered and released by the Whitehouse knowingly then they either expected it never to be critically examined, or they thought it would be discovered, and if the latter, then it is more likely being used for the smoke, in which case, what is behind the smoke screen?
Whatever the case, having the twittersphere and news caught up in their usual histrionics is not unfamiliar territory for Trump. He seems to thrive on that battlefield so it's probably counter productive to engage him there - but people can't seem to help themselves.