Also, the two transactions will most likely be treated as separate completed gifts despite the fact that they were made in the same tax year.
A completed gift merely requires donative intent, delivery, and acceptance.
There will be no tax due unless, in the unlikely event, you have exceeded the lifetime exemption (currently over $13 million).
The alternative here would be to argue that the initial transfer was in the nature of a mistake and the return was done to rectify that mistake.
