Im no senior admin but heres my view
i watched the whole demo and i don't see anything extremely fishy. His timing and aim was just good imo, and i also heard your teammates saying that he was looking at different directions before 1 hitting you, on the demo he sprayed you down, you were getting the wrong idea there too. I see element as a new player with experience from cs, the teammates on your team, especially legend who accuses people of cheating as well as hating on good players, accusing element multiple times along with your teammates, this just made it seem that it was clear he was cheating since you all were agreeing, which made him get banned.
I suggest you watch the demo, i noticed the way he plays mid was usually the same.

Edit- I play cent late at night with 100 ping, Element has around the same playtime as me, also with better ping.