Not to get political.. buy why wouldn't just washing it and generally treating it respectfully be good enough (Like, why waste a perfectly nice looking flag?)
Intentionally throwing one's national flag on the ground and stomping on it... that's one thing. But just dropping it by mistake? People make mistakes, it shouldn't be considered bloody treason :p
Then again, I'm one of those people who avoids ever addressing 'someone of station' as 'Your Grace', 'Your Honour', 'Your Highness', etc. If I were ever in the situation of being expected to do so, I'd be very uncomfortable and would try to get away with "Sir" or "Madam". I don't believe anyone deserves such obsequious subservience. Guess I'd be dead if I'd been born a few hundred years ago.