goodbye no offence taken , I assure you! I see both sides of the marking fence! I'm meticulous because I know how much these results matter but I don't know how typical I am. I'm shocked that such a bad mistake wasn't picked up, though.
At my college we put in for remarks if the student is 1 or 2 marks off the next boundary - we probably win 2 of them a year!
I really like the fact that Edexcel makes their papers available online so teachers can see the marking. There is no excuse for other boards not doing this and charging just to see the paper has been marked properly.
Just to clarify, remarks don't technically exist anymore but you can ask for the paper to be reviewed and if a question has been wrongly marked the mark will be adjusted and the grade may be changed. However in English, for example, if the marker got the correct band but maybe put 1 mark less than the 2nd examiner might have done, it won't change. (That's usually ok unless you were counting on that 1 mark, I suppose!)
That said, I would challenge any weird results.