I watched the video.
At the start of it, you have Akarat’s Champion active but around 2 seconds into the video it drops and the cooldown on it has not expired so you cannot re-cast it yet. At that point, your hero is subject to the move and attack speed slowing effect of your cubed Stone Gauntlets - that’s the blue buff icon with a 5 on it, which is active for the entire time your hero is alive.
Akarat’s Champion does not become available until 6 seconds into the video and, even after it becomes available, you do not re-cast it.
If Akarat’s Champion drops, and the slow begins to take effect, re-casting it will not cancel the slow until after the current animation completes.
Your own video demonstrates that the slow happened because you let Akarat’s Champion expire around 2 seconds into the video. You died because a rotating laser was dropped at your feet and you couldn’t move out of it fast enough, due to the five stacks from Stone Gauntlet, which was causing a 100% movement speed detriment.