Let's say you discovered the gift you gave someone was "re-gifted" to someone else. How would you react? There in lies the danger of re-gifting anything. You have no control over where it might end up or if the trail of discovery could be traced back to you as the original giftee.
A version of this happened to me when I took a bottle of wine over to M.L.'s house who was hosting Susan and I for dinner. In this case it was totally innocent as I had just pick any bottle of wine from our wine cabinet. However this bottle just happened to be the exact bottle the M.L. had brought over to my house two weeks prior for a Vistage social that Susan and I were hosting.
I immediately put two and two together when M.L. commented on how much he enjoyed that brand of wine. It was the joke of the evening that I had "re-gifted" the exact bottle of wine back to it's original owner. Quite a potentially embarrassing situation, but luckily with friends like the M.L.s not an issue.
The moral of the story: "He who gifts should be flattered to get it back."