sometimes you would have to see, you may be just standing beside the official photog or a person from the press. this would cause similarity between your photos, you would need to have enough points to prove that the pic is yours before goin to sue them like tat is mention.
if you really find that both are same, go to the company first then if things get worst go to court and charge them under the copyright infringment law. you may get high compensation if you win*not sure also*, cos sg is promoting good copyright practise.
all the best! Happy Festive Season