Mitchell was cited under Law 10.4 (j) Lifting a player from the ground and dropping that player into the ground whilst that player's feet are still off the ground, such that the player's upper body comes into contact with the ground. Judicial Officer, Nigel Hampton QC imposed the one match ban.
The Appeal was heard by Justice Lex Mpati from South Africa via video conference on Wednesday, 3 July. Having reserved his decision of the incident Mr Mpati said he was not persuaded that the Judicial Officer was wrong in his finding.
"Having heard all of the evidence and reviewed the video I conclude Mr Mitchell lifted the British & Irish Lions player Simon Zebo," Mr Mpati said.
"I also concluded that there was a dropping of Mr Zebo in that, unsupported, his upper body fell to the ground whilst both the legs were still being held up and off the ground and that the player's body came into contact with the ground."
While dismissing the Rebels appeal Mr Mpati also declined to interfere with the one match ban imposed by the Judicial Officer. Mitchell's one match suspension remains in place and will be fulfilled following the Rebels next Super Rugby fixture on Friday 12 July.