What you have to do is use the command setflag right before (or after, I forgot) hidesprite. Then you go to advance map, and go to the person, and look at their person ID, and replace 0000 with the flag. So for example, in the script but setflag 0x1200, so in the Person ID make it 1200.
#org @before
=[PLAYER's name]: what was that?\n???:I blew up the town\p[PLAYER's name]: you monster!\n???:you want a fight\p???: bering it on!
hidesprite 0x800F
#org @after
= WHAT?!
hidesprite 0x800F