many high-optioned BMWs come with staggered tires from the factory, the E39 M5 was - so for a dealer to fail to properly train its employee is unexcusable... the dealer should be insured against such an event and if he is not, it is too bad - they owe you a new wheel... if there is nothing else damaged, you should be fine, this incident should be logged in the notes though - in case if later, down the road something develops in the upper control arm, you might have an argument with the BMW NA...