such a perfect storm of events would have to take place, in order to be 'accidentally' burned alive.
he climbs down, and isn't heard.
he becomes stuck, doesn't yell for help.
the owner happens to decide right then to start a fire.
the burglar doesn't yell when the wood is prepared.
the owner is unable to stop a small fire he's just starting, and has to run for an extinguisher which doesn't arrive in time.
OR.... burglar tries chimney. Owner starts fire. Owner realizes it may be murder (or house fills with smoke), puts it out after man is dead.
I'm fine with him shooting, stabbing, or burning an intruder. This is america, you don't go into houses without knocking, it's a bad ending. BUT so much would have to occur for this to be an accident, I'm not buying it.