I love the English language. It has so many vagaries in grammar and vocabulary. I posted on another thread how an identically sounding word can mean the opposite of itself; eg Raise/Raze. Can you think of any others?
How about left and left: Two men in a room, one left, one left. Which means one stayed. I had some fun with this one with some foreign ESOL students last week.
Or this. In a test which included a question on the use of the word "had", two friends called Had and Hadd each gave a different answer. With that in mind, how do you punctuate the following so that it makes sense?
Had had had had Hadd had had had had had had had been correct
You can get them in french too:
Je suis ce que je suis, mais je ne suis pas ce que je suis. Parceque ce que je suis est un ane. Apologies if the spelling is wrong it is about 30 years since I did French at school. For some reason this stayed with me. It means I am what I am, but I am not what I follow. Because that which I follow is a donkey.
Well not what you are looking for, but the one (two really) that has always puzzled me is flammable, and inflammable - both basically are understood to mean the same thing.
Or, another variation on your example - the one on the right was wrong, but the one on the left was right.
There is a German one which could cause confusion for the unwary.
The main meaning of Rock is skirt, but it used to be used for a man's jacket as well and it still has that sense in South Germany and Austria.
I realise that these words aren't necessarily opposites but I imagine many foreign students studying english, have a few less than complimentary words of their own to use.
The problem with the list in TCL's link is that some of the words do not actually mean what some users of them think they mean i.e. they are being misused. Does that still fit your criteria or are you looking for words with "official" definitions that are 'autoantonyms' or 'contranyms'?
Examples of those that would fail the test:
Splice - never means cut (confused with slice?)
Literally - never means virtually, figuratively
Sometimes it's because the usage is (or seems to be) the result of a mistake. NASA uses 'nominal' to mean 'correct, the expected value'; so, 'the shuttle is moving at a nominal 17500mph'. Correct usage would require that a value or amount described as nominal would be very small.
On other occasions English and American have opposite meanings. In English to table a motion means to propose it. In American to table a motion means not to propose it, i.e. leave it on the table and walk away.