Why wouldn't the local cops look in Drake's trunk the second time he left the Embassy with the pianist? They would have thought their prisoner was still in the building, and that only the pianist left the first time.
When James Carpenter first meets his double, Oscar Schumak (pronounced by Drake as; 'SHOO-mac'), he tells Drake he doesn't wish to get 'mister Sumac' (pronounced; 'SUE-mac') involved.