That TV was rigged up to something, My and my friend have shot TV's before... Only with .22's out on his farm... The TV (even if plugged in) won't start on fire. It'll smoke due to the phospherous imbedded in the screen mixing with the gasses in the tubes.. But that's about it.
If you watch that video on Youtube, You can see that they had poured some flamable thing inside it.. Because half way through the fire strarts dripping out.