I recently wrote a paper, and the examiner picked me up on using 'due to' when apparently I should have been using 'owing to'. I understand that there is some difference between them, as was discussed here. My question is however, should I worry myself with using one in place of the other? Has their distinction fallen out of popular discourse?
I am still of the opinion that each of your idioms has a specific usage:
"Owing to" is used adverbially:
He lost < owing to his attitude.
I am winning < owing to my perseverance.
"Due to" is most often used adjectivally as a predicate adjective.
His loss is due to his attitude.
My victory is due to my perseverance.
That being said, you are quite right that they are used interchangeably by almost everybody in modern usage.
The only reason I even care is because I am antiquated and anachronistic in my opinions, so I would not worry myself over it if I were you.
Have a nice day.
"Due to" is considered nonstandard when used in phrases where "owing to" would normally belong.
And so, such phrasing as "the match was canceled due to the rain" should be best avoided in formal or careful prose.