iPhone dev Stupidity 9

* Trying to load a mismatched class from NIB.

childController = [[DisclosureButtonController alloc] initWithNibName:@"DisclosureDetail" bundle:nil];

When the class in .nib file is assigned as DisclosureDetailController while trying to load it as DisclosureButtonController will definitely cause an error.

There's no runtime check. The error will be triggered when you trying to assign a non-existing property (which is in DisclosureButtonController but not in DisclosureButtonController.