These types of videos are always debunked if the video shows the player's cursor. The player's cursor, even for a millisecond, would show itself hovering over a champion's portrait or the minimap.
There are three directions for these potential human errors:
- Minimap - Toward the specified direction.
- Ally's Portrait - Toward the direction of your specified ally.
- Your own portrait - Backward.
As seen in this video, you are playing on the team that spawned on the top side. So commonly, you have to aim down toward your screen, which so happens to be where your own champion's portrait would be. Assuming that you have your screen around your own champion, your enemies would be close to your bottom HUD, which includes your own champion's portrait. The result actually may be considered evidence of your mistake. Nami shoots right behind her, which is a common result of hovering over your own portrait.
In consideration of Riot that may be roaming this board, this probably is not a good bug report as it doesn't give them anything else that is different from other false bug reports. It's likely a human error. You'd have to get a video of your game with your cursor and stuff to help them get a lead.
One comment,
Did you have your cursor over the minimap or one of the teammate icons?
Can you say the same for your own icon?