re: Does it matter if they lie...
While it's true they're not immune to exaggerating a story or putting more bias than many would like them to, if they were cought lying, they 'd have their boss removed or at least the journalist who made the lie removed.
People can be replaced, but the BBC will stay. Governments can also be replace, BTW.
I'm sure they have so many sources and journalists and ethics and too much of a worldwide impact that it would be very difficult to prove the BBC were blatantly lie as they have a reputation to defend.
Raoul