First hand account witnesses are often inaccurate. Other things we might know, if the guy who pushed the shooter had any criminal arrests and convictions?
at least 3 and up to 5, one of which (at least) was a felony
You're right, witnesses can be inaccurate or false but videos are generally objective.
The fact that you have a criminal record does not change your civil rights when it comes to others shooting you. It's highly doubtful that Drejka knew McGlocktons criminal record. What's telling is that McGlockton was unarmed and the video shows that he stopped and started backing up once the gun was presented. I can understand that being pushed to the ground can trigger (no pun intended) an emotional and adrenalin response. Police and military are trained to not overreact when adrenalin is pumping. When you carry, you have a great responsibility. As Ive told family members, when that bullet leaves the barrel, there is no recall. Based on the video, I think Drejka should have been arrested followed by an investigation by FL AG. Unless I misunderstand FL Stand Your Ground rule, the sheriff misapplied the law.