That doesn't make sense. If you own 50K shares, and then 'short' against those 50K by short selling 50K, your just sold your original 50K........otherwise if you still HAD your original 50K, and sold 50K, then there would be a 50K naked short out there.....You would have just 'created' 50K shares..........What shorting means is you BORROW the shares from somebody and then sell them. The person that you borrowed them from no longer has them......cause you sold em.......and you have an obligation to buy them back at some point to return the shares you borrowed.
NOW. Depending on how the bookkeeping is being done nowadays....this seems like a very RIPE situation for actually NSS'ing a stock....I wonder if that's one of the ways they do it.............z