_Nickolai_ is obviously using anti-knockback, I can guarantee that he will be banned if you report him, he also had some other suspicious activity after 0:15 but I should just report him for anti-knockback. It's definitely not lag, this looks different.
EDIT: I just checked the appeal site and I noticed that _Nickolai_ was banned by Buuuddy for use of illegal clients yesterday.
There us no need to report him since he's punished already.
It really looks like flasetoglobal is using killaura (maybe even b-hop) although the amount of evidence of him is pretty short, I would just report him and let a staff member decide if it's enough evidence or not.
He has been banned by the anti-cheat before so this might increase your chance of your report getting approved. I don't think he has learned his lesson.
You can report at:
https://reports.cubecraft.net/
I wish you best of luck!