Firstly, I don`t know you or read your application so this is a shot in the dark here, but mistakes that are made now days on application forms, cv`s ete..
BA relies heavily on application process on line.
Now I don`t know what questions they were/are asking but guessing customer service type questions, and asking this to be answered in x number of words. So if they want 100 words, they want 100 words, not 104.
They maybe looking for "key" words (not the standard helping with children babies and old people and I love ponies answer..
)
Next. Easy mistakes such as spelling and sentence which mean nothing and woffle on about your aunt in Australia.. your wondering now where`s this going? Exactly! So is the person reading your application.
If you knocked out your application in an hour then I doubt you would be successful. It needs careful planning, rough workings on paper, with possibly several attempts and over a couple of days as new ideas come into your head which could improve your answers.
Then type it out via the internet. But don`t send it straight away. Print it out. Read it though. Make any touch ups necessary, eg spelling, punctuation, capital letters, did you make any typo`s?
And the little favourite is the use of American spelling of words and text messaging shorting of words used in application forms.. erm no not good.
Hope this helps