"We look over Jon's shoulder as the fire sweeps toward the throne — not the target of Drogon's wrath, just a dumb bystander caught up in the conflagration." - from the official Game of Thrones finale script. Drogon didn't burn the Throne. Turns out dragons are not smart.
Mr. Burns was admitted to a local hospital where he was pronounced dead. He was then transferred to a better hospital where his condition was upgraded to 'alive.'