Multitasking isn't perfect. I believe there are some kinks with it.
It's all enforced by the sandbox each application is run in. Pretty difficult for an app to try to throw kinks into the system. Again, if none of the icons are present then there is no multi-tasking going on. Those are done by the OS. Not the app. An app can't be multi-tasking and not show the relevant icons.
Plus those are the only ways you can multi-task. It's not like a developer can go and create their own way of doing it.
Sorry you're wrong, I don't see there being any bugs to this. It's a perception thing.