Artistic Licence or Bad English

As one of the pedants who greatly enjoyed Eats, Shoots and Leaves, the ultimate English grammar book, I am often distressed by incorrect use of English in song lyrics, in particular when the correct words would have fitted perfectly well with the music and the rhyme.

Of course, even Queen abused the language when they felt like it, but the other day I came across a great, easy-listening song where virtually every line is incorrect. The song is "If I Was a River" by Tina Arena; its very title makes me cringe!

Let's see: a phrase expressing doubt requires the conditional tense, as far as I remember. So it should be "If I Were a River". How would that leave the song? Sounds OK to me. I tried it out on my 9 year-old son, translating it into Portuguese: "Se eu fui um rio". He corrected me immediately: "Se eu fosse"! So what is it with these people? I guess the options are:

1. English is not the songwriter or performer's first language;
2. The phrase is correct under "American English" grammar rules ("anything goes!")
3. Nobody gives a damn, as long as it sells!

So. Rant over. I'll just retreat to my Financial Times and G&T!