They either both cheated and Garrosh got wtfpwned or they both didn't cheat and Garrosh got wtfpwned.
Garrosh was wearing armour, just because he had no "shirt" doesn't negate the leather/plate.
Please don't just copy and paste from wowpedia. Those were the ancient Mak'gora rules, if you look at Garrosh vs Thrall first Mak'gora you'll see that there was no blessing, Garrosh was in full-plate and Thrall was using his spells willy nilly. There have been other Mak'gora's since and spells we're used.
End of the day, Garrosh got the chair.
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I'll just leave this here, a post I made ages ago.
http://www.mmo-champion.com/threads/...1#post35220401
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oh and why not, add even more evidence.
http://www.mmo-champion.com/threads/...1#post35183951