I've looked at this coin very closely and I agree the 5 is rotated.
You maybe be able to see this better in this picture, I could only rotate the image in 90 degree increments, so I couldn't get the 5 to be exactly upright, but if you compared it to the 5 on this regular coin you can see that it is a 5.
If you open the first image in another tab you should be able to click it and get it to enlarge, then clicking between the two tabs and you can clearly see on the OP's coin it is a rotated 5.
I'm not sure how the 5 would've got rotated, but it's doesn't look to be a coin that has been altered, it looks like it came from the mint that way, IMHO
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