I put a Conkeldurr up for Rhyperior on the GTS, but I got a LV 30 Rhydon. What happened?
Either you mixed up the names and the Pokémon evolved or hacks were used.
I can’t tell you what hacks tho.
Actually you don't trade the held item with a Pokémon. Before you put it in the GPS it tells to remove the item.
Therefore the protector was removed and it didn't evolve.