Ah! That's so sad but, hey, BoA will be performing for a long time, I'm sure you'll get the chance again!
I had a friend whom I met from Boajjang go to one of the SM concerts in Cali. She was right next to the stage and got a wave from both BoA and Changmin of TVXQ (my two biases of kpop for sure). I lived in AZ at the time and had actually planned to go meet her down there so we could go together but because of money problems last minute I had to stay home.
Same thing happened when Utada Hikaru went to Cali for her In The Flesh concert, except I got snowed in. Maybe I'm just destined to never see my favorite artists live xD