I can't read the word "disgrace" and not picture it in a Daily Mail headline. It's the go-to word of people who talk purely in hyperbole.
If you feel you can judge the amount of respect someone holds for another group based on whether they sing or not then you're weird, sorry.
It isn't simply a matter of respect it is about good manners and knowing how to conduct oneself.
I believe Corbyn was singing - in his head at least, though it was likely to be the Red Flag not our national anthem.
I too felt affronted by Corbyn's demeanour, dress code and the fact he couldn't bring himself to sing our national anthem.
At least I can draw comfort from the fact he will never be PM.