The following excerpt is from a scene from Sword Art Online, where Kirito and Asuna are discussing whether or not the killer they are pursuing is a ghost or not. Asuna seems to think it is, but Kirito is unconvinced (because the killer had used a teleporting crystal). Kirito says:
いや、そんなことは絶対にない。そもそも幽霊だったらさっきも転移結晶なんて使わないで
I'm going to take a guess that the なん (a more emphatic version of なの?) is providing the secondary information for his explanation (the "ghost" used a teleport crystal), and the て is the quotative particle (usually って but て because it's following ん?). Or is て loosely connecting the first clause with the second clause?
I could understand what he was saying in this sentence, but I really don't understand the grammar here or how it is operating structurally :( I would really like to know!