I checked the game logs. Nobody objected except you. If majority of the team object that he sells the items it is reason of ban. Please check the rule once again. I mentioned in red.
Forum (#post_forum) Ingame (#post_ingame)
Ingame Rules
6. Player must not abuse Share Control given to him:
a) Player is allowed to use leaver (his hero, courier, items etc) in the game, but it is forbidden to feed an opponent with him on purpose.
b) Selling (hero-sell instead of team-sell) or taking leaver's items for yourself is only allowed if the majority of the team agrees to (or doesn't object against) it.
c) Destroying , hiding, stealing items, that belong to an ally is not allowed.
d) Controlling (using skills, moving etc) a shared allied hero without clear permission is not allowed.
e) Unsharing the courier after it was upgraded by another player is not bannable.
Note: Own profit selling sanctions are applied only when reported by own teammates.
Note: You can retrieve your items from courier after getting unshared by using the "Pickup all items" spell in your circle.
!Denied