Remember the 2007 LAX discovery of a stowaway on a BA 747?
Dead stowaway at LAX could be from Cape Town | The San Diego Union-Tribune
I always thought it slightly embarrassing that it it took a week and 3 or 4 trips through LHR - with presumably as many pre-flight walkarounds - before the body was finally spotted in LAX. Well, could have been worse, it could have been unlatched cowlings.