FIFA. Does anybody know how too ...

I was playing a head to head season match the other day and when my opponent had a corner he managed to push all 10 outfield players up in to my six yard box. Does anbody know how he did this? I know you can change the team mentality to ultra attacking and push your goalie up etc before the corner is awarded but he managed to do it whilst his player was about to take the kick. Ive tried searching on the internet but not found anything out. It might be that im missing something obvious in the quick tactics ect but i cannot for the life of me figure it out!