first of all her setup isnt right. i hope you arent serious in saying the basking light is IN the habitat. it can seriously burn the iguanna is he gets to it.what kind of uvb light does she have how far from the iguanna is it? a heatpad isnt very good. does she monitor the humidity and the heat with a hygrometer and thermometer? what does she feed it? how big is the enclosure. a lot of these things could be a factor why the iguanna turned mean. another thing is he should be acclimated. and he cant be acclimated untill he has a proper habitat. can you awnser those questiuons to me and then ill try to help you out.
iguannas are extremely hard to take care of compared to other reptiles but if you know what your doing their great.