Not all that surprising. Recently I had to get some stitches (chain link fence 1, toe 0) and told the nurse that I was allergic to neosporin. After the physician's assistant stitched me up he opened up a tube and was about to put some neosporin on the wound before I asked him what was in the tube and stopped him. The ink wasn't even dry on the form which said I was allergic to it.
Wow, good you were viligant.