She's not flat. In fact, the F# that she slides down to is slightly sharp. Actually, I would guess that if I throw it through Melodyne the A she sustains on that note will look auto-tuned.

You might not like the tonality of it (there's little-to-no vibrato on it which can make a note sound dead) but it's not out of tune.

Nobody will ever beat Simon Lebon's howler during View to a Kill at Live Aid
That Fatal kiss,is all We NEEEEEEEEEEEEED

There's a Whitney Houston song from the album Whitney called Where You Are.

In the first verse she goes ever so slightly off singing "magazine" before recovering quickly.

Might just be my ears but it sounds awful!

Having said that I can't sing to save my life so most probably my ears!