Before I came to England the word "sorry" was for me the easiest word to learn and the hardest word to say, but once you are here you realise that the only thing you have to learn is how many times you have to say it and always be ready to use it.
This word has too many things behind its appearance,
Firstly, as I said you always have to be ready to use it any time, even in the most stupid of situations because otherwise it could be interpreted as very rude.
Secondly, you can hear one million times the words "Sorry" and "Please" and nothing has to do with famous English manners. On most occasions when somebody use "Please" really is demanding something and when somebody use "Sorry" you know they are not feeling anything at all about what they did. I mean, if someone hit you with intention, you couldn't ask for explanation if he has already said "Sorry" before because you don't have nothing to do when someone look at you smiling and telling the magic word.
And finally, in the other hand you will find people that in spite of it was your fault, they will say "Sorry" too, in that moment you will think the situation is completely surrealist.
As conclusion, it doesn't matter the meaning or the context, just say Sorry.