2 counterfeit memberships received as gift instead of one?

One player, who decided to join our guild, has sent a Counterfeit Membership as a gift. I've accepted and upgraded the guild house.
Then, after a few seconds I have checked the mails and there was another mail with a Counterfeit Membership. I have assumed that it is due to the lags, so I have accepted and put it on the guild house again, still assuming that only one will be accepted.

Surprisingly, the count increased by two. However, I can not tell if it was a duplicate or somebody else has sent me another gift. I've asked around, but found no one who sent a gift at that time.