Maybe I can give you another tip which might be less helpful when you need the chords to some particular song now but much more if this should happen again in the future:
Try to learn as many songs with - uhm - acceptable chords as possible. Hearing ("earing") is learned by experience, you can't ask somebody to teach you how to hear, and many abilities we are sometimes impressed of are also just accomodation of the one who shows them to things he often has to cope with. This will also give you the ability to notice different chords you might hear and to compare: You can only compare one thing with another one if you KNOW it.
And - doing many songs just correctly is much better performance that doing one song perfectly over and over again, isn't it?