Collectors edition

A few days back,which was actually on a friday.My manager found something interesting.She found a 50 cent coin that actually doesnt look like your ordinary 50 cent coin.It was gold in colour and slightly thinner.However,it was in the coin roll for our cash register.The coin roll came directly from the bank so it can't be fake can it?It weighs the same as an $1 coin and its gold like a $1 coin.I can only suspect that a coin thats supposed to be worth $1 had been accidentally dropped in the 50cents mould instead.I wonder...