I would do the smell test and if it seems okay then use it or put it in the fridge. In my experience DD will reject milk that is funny. Sorry for this; not fun to find, I can imagine your surprise. I had this with milk in the car once, and was devastated (except it was days later when I went looking for the bottle bag...)
Re: I forgot 12oz on the counter overnight
whoever said "no use crying over spilt milk" never breastfed.
I hope you can still use it today! 12 oz would be a terrible loss. : (
This. Just jumping in to let you know I feel for you!
Sooo true